Method of manufacturing semiconductor device, substrate processing apparatus, and recording medium

ABSTRACT

A method of manufacturing a semiconductor device includes forming a thin film containing a specific element, oxygen, carbon, and nitrogen by performing a cycle a predetermined number of times. The cycle includes supplying a specific element-containing gas, supplying a carbon-containing gas, supplying an oxidizing gas, and supplying a nitriding gas. The act of supplying the nitriding gas is performed before the act of supplying the specific element-containing gas, and the act of supplying the carbon-containing gas and the act of supplying the oxidizing gas are not performed until the act of supplying the specific element-containing gas is performed.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/251,243 filed on Apr. 11, 2014, which is a continuation of U.S.patent application Ser. No. 13/963,027 filed on Aug. 9, 2013, whichissued on May 20, 2014 as U.S. Pat. No. 8,728,954, which is based uponand claims the benefit of priority from Japanese Patent Application No.2012-179926, filed on Aug. 14, 2012, the entire contents of which areincorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a method of manufacturing asemiconductor device which includes a process of forming a thin film ona substrate, a substrate processing apparatus, and a recording medium.

BACKGROUND

As semiconductor devices are miniaturized in size, the demand forreducing a parasitic capacitance between a gate and a source of atransistor is increasing. For this reason, a film (e.g., low-k film)having a relatively lower dielectric constant is considered inmanufacturing semiconductor devices, instead of a silicon nitride film(Si_(x)N_(y) film, hereinafter simply referred to as “SiN film”), whichis conventionally used as a sidewall film or the like. In a siliconoxide carbon nitride film (SiOCN film) in which oxygen (O) and carbon(C) are added into the SiN film, a low dielectric constant is realizedby adding O, and a wet etching resistance or a dry etching resistancewhich is deteriorated by adding O can be recovered or improved by addingC.

It is known that the SiOCN film is formed, for example, by performing acycle a predetermined number of times, the cycle including: a process ofsupplying a silicon-containing gas to a heated wafer in a processingchamber; a process of supplying a carbon-containing gas; a process ofsupplying a nitriding gas; and a process of supplying an oxidizing gas,which are sequentially performed. Recently, a high dielectric constantinsulating film (high-k film) is used as a gate insulating film oftransistors, and thus lowering a film-forming temperature of a thin filmformed near a gate, such as a sidewall film, is increasingly required.The low temperature range may be, for example, equal to or less than 600degrees C., for example, equal to or less than 450 degrees C. However,when the film-forming temperature is lowered to the low temperaturerange, a deposition rate of a thin film is reduced, causing a lowproductivity of semiconductor devices.

SUMMARY

The present disclosure provides some embodiments of a method ofmanufacturing a semiconductor device, a substrate processing apparatus,and a recording medium which can prevent a deposition rate from beingreduced when forming a thin film, containing a specific element, oxygen,carbon, and nitrogen, in a low temperature range.

According to some embodiments of the present disclosure, there isprovided a method of manufacturing a semiconductor device, including:forming a thin film containing a specific element, oxygen, carbon, andnitrogen on a substrate by performing a cycle a predetermined number oftimes, the cycle including: supplying a specific element-containing gasto the substrate; supplying a carbon-containing gas to the substrate;supplying an oxidizing gas to the substrate; and supplying a nitridinggas to the substrate, wherein in the act of forming the thin film, theact of supplying the nitriding gas is performed before the act ofsupplying the specific element-containing gas, and the act of supplyingthe carbon-containing gas and the act of supplying the oxidizing gas arenot performed until the act of supplying the specific element-containinggas is performed after the act of supplying the nitriding gas isperformed.

According to some other embodiments of the present disclosure, there isprovided a substrate processing apparatus, including: a processingchamber configured to accommodate a substrate; a specificelement-containing gas supply system configured to supply a specificelement-containing gas to the substrate in the processing chamber; acarbon-containing gas supply system configured to supply acarbon-containing gas to the substrate in the processing chamber; anoxidizing gas supply system configured to supply an oxidizing gas to thesubstrate in the processing chamber; a nitriding gas supply systemconfigured to supply a nitriding gas to the substrate in the processingchamber; and a controller configured to control the specificelement-containing gas supply system, the carbon-containing gas supplysystem, the oxidizing gas supply system, and the nitriding gas supplysystem such that a thin film containing a specific element, oxygen,carbon, and nitrogen is formed on the substrate by performing a cycle apredetermined number of times, the cycle including: supplying thespecific element-containing gas to the substrate, supplying thecarbon-containing gas to the substrate, supplying the oxidizing gas tothe substrate, and supplying the nitriding gas to the substrate, and inthe act of forming the thin film, the act of supplying the nitriding gasis performed before the act of supplying the specific element-containinggas, and the act of supplying the carbon-containing gas and the act ofsupplying the oxidizing gas are not performed until the act of supplyingthe specific element-containing gas is performed after the act ofsupplying the nitriding gas is performed.

According to yet other embodiments of the present disclosure, there isprovided a non-transitory computer-readable recording medium storing aprogram that causes a computer to perform a process of forming a thinfilm containing a specific element, oxygen, carbon, and nitrogen on asubstrate by performing a cycle a predetermined number of times, thecycle including: supplying a specific element-containing gas to thesubstrate; supplying a carbon-containing gas to the substrate; supplyingan oxidizing gas to the substrate; and supplying a nitriding gas to thesubstrate, wherein in the act of forming the thin film, the act ofsupplying the nitriding gas is performed before the act of supplying thespecific element-containing gas, and the act of supplying thecarbon-containing gas and the act of supplying the oxidizing gas are notperformed until the act of supplying the specific element-containing gasis performed after the act of supplying the nitriding gas is performed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view illustrating a configuration of a verticaltreatment furnace of a substrate processing apparatus, in which aportion of the treatment furnace is shown in a longitudinal sectionalview, according to some embodiments.

FIG. 2 is a schematic view illustrating a configuration of the verticaltreatment furnace of the substrate processing apparatus, in which aportion of the treatment furnace is shown in a sectional view takenalong line A-A in FIG. 1.

FIG. 3 is a block diagram illustrating a configuration of a controllerof the substrate processing apparatus, according to some embodiments.

FIGS. 4A and 4B are timing diagrams illustrating a gas supply timing ina first sequence and a gas supply timing in a modification example ofthe first sequence, respectively, according to some embodiments.

FIGS. 5A and 5B are timing diagrams illustrating a gas supply timing ina second sequence and a gas supply timing in a modification example ofthe second sequence, respectively, according to some embodiments.

FIGS. 6A and 6B are timing diagrams illustrating a gas supply timing inan example of the present disclosure and a gas supply timing in acomparative example, respectively.

FIG. 7 is a view showing measurement results of film thicknesses ofSiOCN films in the example of the present disclosure and the comparativeexample.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments, examples ofwhich are illustrated in the accompanying drawings. In the followingdetailed description, numerous specific details are set forth in orderto provide a thorough understanding of the present invention(s).However, it will be apparent to one of ordinary skill in the art thatthe present invention(s) may be practiced without these specificdetails. In other instances, well-known methods, procedures, systems,and components have not been described in detail so as not tounnecessarily obscure aspects of the various embodiments.

Various embodiments will be now described with reference to thedrawings.

(1) Configuration of Substrate Processing Apparatus

FIG. 1 is a schematic view illustrating a configuration of a verticaltreatment furnace 202 of a substrate processing apparatus, according tosome embodiments, in which a portion of the treatment furnace 202 isshown in a longitudinal sectional view. FIG. 2 is a schematic viewillustrating a configuration of the vertical treatment furnace 202,according to some embodiments, in which a portion of the treatmentfurnace 202 is shown in a sectional view taken along line A-A in FIG. 1.

The present disclosure is not limited to the substrate processingapparatus of FIGS. 1 and 2, and may be applied to a substrate processingapparatus, for example, including a single-wafer type, hot wall type, orcold wall type treatment furnace.

As illustrated in FIG. 1, the treatment furnace 202 includes a heater207 as a heating means (heating mechanism). The heater 207 has acylindrical shape, and is vertically installed by being supported by aheater base (not shown) that is a holding plate. Also, as describedlater, the heater 207 may function as an activating mechanism thatactivates (excites) a gas with heat.

A reaction tube 203 configuring a reaction vessel (processing vessel) isdisposed inside the heater 207 in a concentric form along the heater207. The reaction tube 203 may be formed of, for example, aheat-resistant material such as quartz (SiO₂) or silicon carbide (SiC),and has a cylindrical shape with an upper end closed and a lower endopened. A processing chamber 201 is provided in a hollow cylindricalportion of the reaction tube 203, and configured to accommodate aplurality of wafers 200, which are substrates. The wafers 200 arehorizontally stacked in multiple stages to be aligned in a verticaldirection in a boat 217 which will be described later.

A first nozzle 249 a, a second nozzle 249 b, a third nozzle 249 c, and afourth nozzle 249 d are installed in the processing chamber 201 to passthrough a lower portion of the reaction tube 203. A first gas supplypipe 232 a, a second gas supply pipe 232 b, a third gas supply pipe 232c, and a fourth gas supply pipe 232 d are connected to the first nozzle249 a, the second nozzle 249 b, the third nozzle 249 c, and the fourthnozzle 249 d, respectively. As described above, the four nozzles 249 a,249 b, 249 c and 249 d and the four gas supply pipes 232 a, 232 b, 232 cand 232 d are installed in the reaction tube 203 to supply a pluralityof kinds of (4 in this example) gases into the processing chamber 201.

Moreover, a manifold (not shown) formed of metal which supports thereaction tube 203 may be installed under the reaction tube 203 such thatthe nozzles pass through a sidewall of the manifold formed of metal. Inthis case, an exhaust pipe 231 described later may be installed at themanifold formed of metal. In this case, the exhaust pipe 231 may beinstalled at a lower portion of the reaction tube 203 rather than at themetal manifold. As described above, a furnace port of the treatmentfurnace 202 may be formed of metal, and the nozzles may be mounted onthe furnace port formed of metal.

A mass flow controller (MFC) 241 a, which is a flow rate controller (aflow rate control part), and a valve 243 a, which is an opening/closingvalve, are installed at the first gas supply pipe 232 a in this orderfrom an upstream direction. Also, a first inert gas supply pipe 232 e isconnected to the first gas supply pipe 232 a at a downstream side of thevalve 243 a. A mass flow controller 241 e, which is a flow ratecontroller (a flow rate control part), and a valve 243 e, which is anopening/closing valve, are installed at the first inert gas supply pipe232 e in this order from the upstream direction. In addition, theabove-described first nozzle 249 a is connected to a front end portionof the first gas supply pipe 232 a. The first nozzle 249 a is installedin an arc-shaped space between an inner wall of the reaction tube 203and the wafers 200. The first nozzle 249 a is vertically disposed alongthe inner wall of the reaction tube 203 to rise upward in a stackingdirection of the wafers 200.

That is, the first nozzle 249 a is installed in a flank of a waferarrangement region, in which the wafers 200 are arranged. The firstnozzle 249 a is configured as an L-shaped long nozzle, and has ahorizontal portion installed to pass through a lower sidewall of thereaction tube 203 and a vertical portion installed to rise from one endside toward the other end side of at least the wafer arrangement region.A plurality of gas supply holes 250 a through which gas is supplied isformed at a side surface of the first nozzle 249 a. The gas supply holes250 a are opened toward a center of the reaction tube 203 so that gascan be supplied toward the wafers 200. The gas supply holes 250 a aredisposed to span from a lower portion to an upper portion of thereaction tube 203 at a predetermined opening pitch. The plurality of gassupply holes 250 a has the same opening area. A first gas supply systemis mainly configured by the first gas supply pipe 232 a, the mass flowcontroller 241 a, and the valve 243 a. Also, the first nozzle 249 a maybe included in the first gas supply system. In addition, a first inertgas supply system is mainly configured by the first inert gas supplypipe 232 e, the mass flow controller 241 e, and the valve 243 e.

A mass flow controller (MFC) 241 b, which is a flow rate controller (aflow rate control part), and a valve 243 b, which is an opening/closingvalve, are installed at the second gas supply pipe 232 b in this orderfrom the upstream direction. Also, a second inert gas supply pipe 232 fis connected to the second gas supply pipe 232 b at a downstream side ofthe valve 243 b. A mass flow controller 241 f, which is a flow ratecontroller (a flow rate control part), and a valve 243 f, which is anopening/closing valve, are installed at the second inert gas supply pipe232 f in this order from the upstream direction. In addition, theabove-described second nozzle 249 b is connected to a front end portionof the second gas supply pipe 232 b. The second nozzle 249 b isinstalled in an arc-shaped space between the inner wall of the reactiontube 203 and the wafers 200. The second nozzle 249 b is verticallydisposed along the inner wall of the reaction tube 203 to rise upward inthe stacking direction of the wafers 200. That is, the second nozzle 249b is installed in the flank of the wafer arrangement region, in whichthe wafers 200 are arranged. The second nozzle 249 b is configured as anL-shaped long nozzle, and has a horizontal portion installed to passthrough the lower sidewall of the reaction tube 203 and a verticalportion installed to rise from one end side toward the other end side ofat least the wafer arrangement region. A plurality of gas supply holes250 b through which gas is supplied is formed at a side surface of thesecond nozzle 249 b. The gas supply holes 250 b are opened toward thecenter of the reaction tube 203 so that gas can be supplied toward thewafers 200. The gas supply holes 250 b are disposed to span from thelower portion to the upper portion of the reaction tube 203 at apredetermined opening pitch. The plurality of gas supply holes 250 b hasthe same opening area. A second gas supply system is mainly configuredby the second gas supply pipe 232 b, the mass flow controller 241 b, andthe valve 243 b. Also, the second nozzle 249 b may be included in thesecond gas supply system. Furthermore, a second inert gas supply systemis mainly configured by the second inert gas supply pipe 232 f, the massflow controller 241 f, and the valve 243 f.

A mass flow controller (MFC) 241 c, which is a flow rate controller (aflow rate control part), and a valve 243 c, which is an opening/closingvalve, are installed at the third gas supply pipe 232 c in this orderfrom the upstream direction. Also, a third inert gas supply pipe 232 gis connected to the third gas supply pipe 232 c at a downstream side ofthe valve 243 c. A mass flow controller 241 g, which is a flow ratecontroller (a flow rate control part), and a valve 243 g, which is anopening/closing valve, are installed at the third inert gas supply pipe232 g in this order from the upstream direction. In addition, theabove-described third nozzle 249 c is connected to a front end portionof the third gas supply pipe 232 c. The third nozzle 249 c is installedin an arc-shaped space between the inner wall of the reaction tube 203and the wafers 200. The third nozzle 249 c is vertically disposed alongthe inner wall of the reaction tube 203 to rise upward in the stackingdirection of the wafers 200. That is, the third nozzle 249 c isinstalled at the flank of the wafer arrangement region, in which thewafers 200 are arranged. The third nozzle 249 c is configured as anL-shaped long nozzle, and has a horizontal portion installed to passthrough the lower sidewall of the reaction tube 203 and a verticalportion installed to rise from one end side toward the other end side ofat least the wafer arrangement region. A plurality of gas supply holes250 c through which gas is supplied is formed at a side surface of thesecond nozzle 249 b. The gas supply holes 250 c are opened toward thecenter of the reaction tube 203 so that gas can be supplied toward thewafers 200. The gas supply holes 250 c are disposed to span from thelower portion to the upper portion of the reaction tube 203 at apredetermined opening pitch. The plurality of gas supply holes 250 c hasthe same opening area. A third gas supply system is mainly configured bythe third gas supply pipe 232 c, the mass flow controller 241 c, and thevalve 243 c. In addition, the third nozzle 249 c may be included in thethird gas supply system. Furthermore, a third inert gas supply system ismainly configured by the third inert gas supply pipe 232 g, the massflow controller 241 g and the valve 243 g.

A mass flow controller (MFC) 241 d, which is a flow rate controller (aflow rate control part), and a valve 243 d, which is an opening/closingvalve, are installed at the fourth gas supply pipe 232 d in this orderfrom the upstream direction. Also, a fourth inert gas supply pipe 232 his connected to the fourth gas supply pipe 232 d at a downstream side ofthe valve 243 d. A mass flow controller 241 h, which is a flow ratecontroller (a flow rate control part), and a valve 243 h, which is anopening/closing valve, are installed at the fourth gas supply pipe 232 hin this order from the upstream direction. In addition, theabove-described fourth nozzle 249 d is connected to a front end portionof the fourth gas supply pipe 232 d. The fourth nozzle 249 c isinstalled in a buffer chamber 237 that is a gas diffusion space.

The buffer chamber 237 is installed in an arc-shaped space between aninner wall of the reaction tube 203 and the wafers 200. The bufferchamber 237 is vertically disposed along the inner wall of the reactiontube 203 in the stacking direction of the wafers 200. That is, thebuffer chamber 237 is installed in the flank of the wafer arrangementregion. A plurality of gas supply holes 250 e through which gas issupplied is formed at an end portion of a wall adjacent to the wafers200. The gas supply holes 250 e are opened toward the center of thereaction tube 203 so that gas can be supplied toward the wafers 200. Thegas supply holes 250 e are disposed to span from the lower portion tothe upper portion of the reaction tube 203 at a predetermined openingpitch. The plurality of gas supply holes 250 e has the same openingarea.

The fourth nozzle 249 d is installed between an end portion, in whichthe gas supply holes 250 e are formed, and an opposite end portion ofthe buffer chamber 237. The fourth nozzle 249 d is vertically disposedalong the inner wall of the reaction tube 203 to rise upward in thestacking direction of the wafers 200. That is, the fourth nozzle 249 dis installed at the flank of the wafer arrangement region, in which thewafers 200 are arranged. The third nozzle 249 c is configured as anL-shaped long nozzle, and has a horizontal portion installed to passthrough the lower sidewall of the reaction tube 203 and a verticalportion installed to rise from one end side toward the other end side ofat least the wafer arrangement region. A plurality of gas supply holes250 d through which gas is supplied is formed at a side surface of thefourth nozzle 249 d. The gas supply holes 250 d, similarly to the gassupply holes 250 e of the buffer chamber 237, are disposed to span fromthe lower portion to the upper portion of the reaction tube 203. Theplurality of gas supply holes 250 may have the same opening area and thesame opening pitch from an upstream side (lower portion) to a downstreamside (upper portion) when a pressure difference between the inside ofthe buffer chamber 237 and the inside of the processing chamber 201 issmall, but when the pressure difference is large, the opening area ofeach of the plurality of gas supply holes 250 e may be set larger, andthe opening pitch of each gas supply hole 250 e may be set smaller atthe downstream side than the upstream side.

By adjusting the opening area or opening pitch of each gas supply hole250 e of the fourth nozzle 249 d from the upstream side to thedownstream as described above, gases may be ejected at the almost sameflow rate from the respective gas supply holes 250 d despite there beinga flow velocity difference. The gases ejected from the respective gassupply holes 250 d are first introduced into the buffer chamber 237, anda flow velocity difference of the gases is uniformized in the bufferchamber 237. The gases ejected from the respective gas supply holes 250d of the fourth nozzle 249 d into the buffer chamber 237 are mitigatedin particle velocity, and then are ejected from the respective gassupply holes 250 e of the buffer chamber 237 into the processing chamber201. Therefore, the gases ejected from the respective gas supply holes250 d of the fourth nozzle 249 d into the buffer chamber 237 have auniform flow rate and flow velocity when the gases are ejected from therespective gas supply holes 250 e of the buffer chamber 237 into theprocessing chamber 201.

A fourth gas supply system is mainly configured by the fourth gas supplypipe 232 d, the mass flow controller 241 d, and the valve 243 d. Also,the fourth nozzle 249 d and the buffer chamber 237 may be included inthe fourth gas supply system. In addition, a fourth inert gas supplysystem is mainly configured by the fourth inert gas supply pipe 232 h,the mass flow controller 241 h, and the valve 243 h. The fourth inertgas supply system functions as a purge gas supply system.

Gas that is supplied may be transferred via the nozzles 249 a, 249 b,249 c and 249 d and buffer chamber 237 disposed in an arc-shapedlongitudinal space defined by the inner wall of the reaction tube 203and end portions of the plurality of stacked wafers 200, the gas isfirst ejected into the reaction tube 203 near the wafers 200 through thegas supply holes 250 a, 250 b, 250 c, 250 d and 250 e opened in thenozzles 249 a, 249 b, 249 c, and 249 d and buffer chamber 237,respectively, and thus, a main flow of the gas in the reaction tube 203follows a direction parallel to surfaces of the wafers 200, namely, thehorizontal direction. With this configuration, the gas can be uniformlysupplied to the wafers 200, and thus, a film thickness of a thin filmformed on each of the wafers 200 can be uniformized. In addition, aresidual gas after reaction flows toward an exhaust port, for example,the exhaust pipe 231, but a flow direction of the residual gas may beappropriately specified by a position of the exhaust port without beinglimited to the vertical direction.

A silicon raw material gas (i.e., a silicon-containing gas containingsilicon (Si)) such as a chlorosilane-based raw material gas, forexample, is supplied as a specific element-containing gas from the firstgas supply pipe 232 a into the processing chamber 201 through the massflow controller 241 a, the valve 243 a, and the first nozzle 249 a. Ahexachlorodisilane (Si₂Cl₆, abbreviation: HCDS) gas, for example, may beused as the silicon-containing gas. Also, when a liquid raw materialhaving a liquid state is used like HCDS under a normal temperature and anormal pressure, the liquid raw material is vaporized by a vaporizationsystem such as a vaporizer or a bubbler, and supplied as a raw materialgas (HCDS gas).

A carbon-containing gas, namely, a gas containing carbon (C), issupplied from the second gas supply pipe 232 b into the processingchamber 201 through the mass flow controller 241 b, the valve 243 b, andthe second nozzle 249 b. A hydrocarbon-based gas such as propylene(C₃H₆) gas, for example, may be used as the carbon-containing gas.

An oxidizing gas, namely, a gas (oxygen-containing gas) containingoxygen (0), is supplied from the third gas supply pipe 232 c into theprocessing chamber 201 through the mass flow controller 241 c, the valve243 c, and the third nozzle 249 c. An oxygen (O₂) gas, for example, maybe used as the oxidizing gas.

A nitriding gas, namely, a gas (nitrogen-containing gas) containingnitrogen (N), is supplied from the fourth gas supply pipe 232 d into theprocessing chamber 201 through the mass flow controller 241 d, the valve243 d, and the fourth nozzle 249 d. An ammonia (NH₃) gas, for example,may be used as the nitriding gas.

A nitrogen (N₂) gas, for example, is supplied from the inert gas supplypipes 232 e, 232 f, 232 g and 232 h into the processing chamber 201through the mass flow controllers 241 e, 241 f, 241 g and 231 h, thevalves 243 e, 243 f, 243 f and 243 h, the gas supply pipes 232 a, 232 b,232 c and 232 d, the nozzles 249 a, 249 b, 249 c and 249 d, and thebuffer chamber 237, respectively.

Moreover, for example, when the above-described gases flow through therespective gas supply pipes, a specific element-containing gas supplysystem, for example, a silicon-containing gas supply system(silane-based gas supply system), is configured by the first gas supplysystem. Also, a carbon-containing gas supply system is configured by thesecond gas supply system. Also, an oxidizing gas supply system, namely,an oxygen-containing gas supply system, is configured by the third gassupply system. Also, a nitriding gas supply system, namely, anitrogen-containing gas supply system, is configured by the fourth gassupply system. Also, the specific element-containing gas supply systemis simply referred to as a raw material gas supply system or a rawmaterial supply system. Also, when the carbon-containing gas, theoxidizing gas, and the nitriding gas are collectively referred to as areaction gas, a reaction gas supply system is configured by the carbongas supply system, the oxidizing gas supply system, and the nitridinggas supply system.

In the buffer chamber 237, as illustrated in FIG. 2, a first rod-shapedelectrode 269 that is a first electrode having an elongated structureand a second rod-shaped electrode 270 that is a second electrode havingan elongated structure are disposed along the stacking direction of thewafers 200 from the lower portion to the upper portion of the reactiontube 203. Each of the first rod-shaped electrode 269 and secondrod-shaped electrode 270 is disposed in parallel to the fourth nozzle249 d. Each of the first rod-shaped electrode 269 and second rod-shapedelectrode 270 is covered and protected by an electrode protection tube275 that is a protection tube for protecting each of the electrodes froman upper portion to a lower portion thereof. One of the first rod-shapedelectrode 269 and second rod-shaped electrode 270 is connected to ahigh-frequency power source 273 through a matcher 272, and the other isconnected to a ground corresponding to a reference electric potential.By applying high-frequency power from the high-frequency power source273 to the first rod-shaped electrode 269 and the second rod-shapedelectrode 270 through the matcher 272, plasma is generated in a plasmageneration region 224 between the first rod-shaped electrode 269 and thesecond rod-shaped electrode 270. Mainly, a plasma source that is aplasma generator (plasma generating part) is configured by the firstrod-shaped electrode 269, the second rod-shaped electrode 270, and theelectrode protection tube 275. Also, the matcher 272 and thehigh-frequency power source 273 may be included in the plasma source.Also, as described later, the plasma source functions as an activatingmechanism (exciting part) that activates (excites) a gas to plasma.

The electrode protection tube 275 has a structure in which the firstrod-shaped electrode 269 and the second rod-shaped electrode 270 areable to be inserted into the buffer chamber 237 in a state where thefirst rod-shaped electrode 269 and the second rod-shaped electrode 270are isolated from an internal atmosphere of the buffer chamber 237.Here, when an internal oxygen concentration of the electrode protectiontube 275 is equal to an oxygen concentration in an ambient air(atmosphere), the first rod-shaped electrode 269 and second rod-shapedelectrode 270 inserted into the electrode protection tube 275 areoxidized by heat generated by the heater 207. Therefore, by charging theinside of the electrode protection tube 275 with an inert gas such asnitrogen gas, or by purging the inside of the electrode protection tube275 with an inert gas such as nitrogen gas using an inert gas purgingmechanism, the internal oxygen concentration of the electrode protectiontube 275 decreases, thus preventing oxidation of the first rod-shapedelectrode 269 or the second rod-shaped electrode 270.

The exhaust pipe 231 for exhausting an internal atmosphere of theprocessing chamber 201 is installed at the reaction tube 203. A vacuumexhaust device, for example, vacuum pump 246, is connected to theexhaust pipe 231 through a pressure sensor 245, which is a pressuredetector (pressure detecting part) for detecting an internal pressure ofthe processing chamber 201, and an auto pressure controller (APC) valve244 that is a pressure regulator (pressure regulating part). The APCvalve 244 is a valve configured to perform/stop vacuum exhaustion in theprocessing chamber 201 by opening/closing the valve with the vacuum pump246 actuated and adjust the internal pressure of the processing chamber201 by regulating a degree of the valve opening with the vacuum pump 246actuated. Mainly, an exhaust system is configured by the exhaust pipe231, the APC valve 244, and the pressure sensor 245. Also, the vacuumpump 246 may be included in the exhaust system. The exhaust system mayadjust the degree of valve opening of the APC valve 244 on the basis ofpressure information detected by the pressure sensor 245 while operatingthe vacuum pump 246, thereby vacuum-exhausting the inside of theprocessing chamber 201 such that the internal pressure of the processingchamber 201 becomes a predetermined pressure (vacuum level).

A seal cap 219, which functions as a furnace port cover for air-tightlysealing a lower end opening of the reaction tube 203, is installed underthe reaction tube 203. The seal cap 219 contacts the lower end of thereaction tube 203 from below in the vertical-direction. The seal cap219, for example, may be formed of metal such as stainless to have adisc shape. An O-ring 220 contacting the lower end of the reaction tube203 is disposed as a seal member at a top of the seal cap 219. A rotarymechanism 267 for rotating the boat 217 is installed as alater-described substrate holder, below the seal cap 219. A rotary shaft255 of the rotary mechanism 267 is connected to the boat 217 through theseal cap 219. The rotary mechanism 267 rotates the boat 217 to rotatethe wafers 200. The seal cap 219 is vertically lowered and raised by aboat elevator 115 that is vertically disposed as an elevation mechanismoutside the reaction tube 203. The boat elevator 115 may lower and raisethe seal cap 219 to enable the boat 217 to be loaded and unloaded intoand from the processing chamber 201. That is, the boat elevator 115 isconfigured as a transferring device (transferring mechanism) thattransfers the boat 217, namely, the wafers 200, to inside and outsidethe processing chamber 201.

The boat 217, which is used as a substrate support, is formed of aheat-resistant material such as quartz or silicon carbide, andconfigured to support the wafers 200 horizontally stacked in multiplestages with the center of the wafers 200 concentrically aligned. Inaddition, a heat insulating member 218 formed of a heat-resistantmaterial such as quartz or silicon carbide is installed at a lowerportion of the boat 217, and configured such that heat from the heater207 cannot be transferred to the seal cap 219. In addition, the heatinsulating member 218 may be constituted by a plurality of heatinsulating plates formed of a heat-resistant material such as quartz orsilicon carbide, and a heat insulating plate holder configured tosupport the heat insulating plates in a horizontal posture in amulti-stage manner.

A temperature sensor 263 as a temperature detector is installed in thereaction tube 203. Based on temperature information detected by thetemperature sensor 263, a state of electric conduction to the heater 207is adjusted such that the interior of the processing chamber 201 has anintended temperature distribution. The temperature sensor 263 isconfigured in an L-shape similarly to the nozzles 249 a, 249 b, 249 cand 249 d, and installed along the inner wall of the reaction tube 203.

As illustrated in FIG. 3, a controller 121, which is a control unit (acontrol part), is configured as a computer including a centralprocessing unit (CPU) 121 a, a random access memory (RAM) 121 b, amemory device 121 c, and an I/O port 121 d. The RAM 121 b, the memorydevice 121 c and the I/O port 121 d are configured to exchange data withthe CPU 121 a through an internal bus 121 e. An input/output device 122including, for example, a touch panel, is connected to the controller121.

The memory device 121 c is configured by, for example, a flash memory, ahard disk drive (HDD), or the like. A control program for controlling anoperation of the substrate processing apparatus or a process recipe, inwhich a sequence or condition for processing a substrate described lateris written, is readably stored in the memory device 121 c. Also, theprocess recipe functions as a program to cause the controller 121 toexecute each sequence in the substrate processing process describedlater to obtain a predetermined result. Hereinafter, the process recipeor control program may be generally simply referred to as a program.Also, when the term “program” is used herein, it may include a case inwhich the process recipe is solely included, a case in which the controlprogram is solely included, or a case in which both of these areincluded. In addition, the RAM 121 b is configured as a memory area(work area) in which a program or data read by the CPU 121 a istemporarily stored.

The I/O port 121 d is connected to the mass flow controllers 241 a, 241b, 241 c, 241 d, 241 e, 241 f, 241 g and 241 h, the valves 243 a, 243 b,243 c, 243 d, 243 e, 243 f, 243 g and 243 h, the pressure sensor 245,the APC valve 244, the vacuum pump 246, the heater 207, the temperaturesensor 263, the high-frequency power source 273, the matcher 272, therotary mechanism 267, the boat elevator 115, etc.

The CPU 121 a is configured to read and execute the control program fromthe memory device 121 c and read the process recipe from the memorydevice 121 c according to input of an operation command from theinput/output device 122. In addition, the CPU 121 a is configured tocontrol flow rate controlling operations of various gases by the massflow controllers 241 a, 241 b, 241 c, 241 d, 241 e, 241 f, 241 g and 241h, opening/closing operations of the valves 243 a, 243 b, 243 c, 243 d,243 e, 243 f, 243 g and 243 h, an opening/closing operation of the APCvalve 244 and a pressure regulating operation by the APC valve 244 basedon the pressure sensor 245, a temperature regulating operation of theheater 207 based on the temperature sensor 263, start and stop of thevacuum pump 246, a rotation and rotation speed adjusting operation ofthe boat 217 by the rotary mechanism 267, an elevation operation of theboat 217 by the boat elevator 115, supply of power by the high-frequencypower source 273, an impedance adjusting operation of the matcher 272,etc., according to contents of the read process recipe.

Moreover, the controller 121 is not limited to being configured as anexclusive computer but may be configured as a general-purpose computer.For example, the controller 121 can be configured by preparing anexternal memory device 123 (for example, a magnetic tape, a magneticdisk such as a flexible disk or a hard disk, an optical disk such as aCD or DVD, a magneto-optical disk such as an MO, a semiconductor memorysuch as a USB memory or a memory card), in which the program is stored,and installing the program on the general-purpose computer using theexternal memory device 123. Also, a means for supplying a program to acomputer is not limited to the case in which the program is suppliedthrough the external memory device 123. For example, the program may besupplied using a communication means such as the Internet or a dedicatedline, rather than through the external memory device 123. Also, thememory device 121 c or the external memory device 123 may be configuredas a non-transitory computer-readable recording medium, which isreadable by a computer. Hereinafter, these means for supplying theprogram will be simply referred to as a recording medium. In addition,when the term “recording medium” is used herein, it may include a casein which the memory device 121 c is solely included, a case in which theexternal memory device 123 is solely included, or a case in which bothof these are included.

(2) Substrate Processing Process

Next, a sequence of forming a thin film on a substrate, which is one ofthe processes of manufacturing a semiconductor device by using thetreatment furnace 202 of the above-described substrate processingapparatus, will be described. In addition, in the following description,operations of the respective parts constituting the substrate processingapparatus are controlled by the controller 121.

Moreover, in order to form a composition ratio of a film to be formed asa stoichiometric composition or another predetermined composition ratiodifferent from the stoichiometric composition, supply conditions of aplurality of kinds of gases containing a plurality of elementsconstituting the film to be formed are controlled. For example, thesupply conditions are controlled such that at least one element of theplurality of elements configuring the film to be formedstoichiometrically exceeds another element. Hereinafter, a sequence offorming a film while controlling a ratio of the plurality of elementsconstituting the film to be formed, namely, a composition ratio of thefilm, will be described.

(First Sequence)

First, a first sequence will be described.

FIG. 4A is a view showing a gas supply timing in the first sequence,according to some embodiments.

In the first sequence, a thin film containing a specific element,oxygen, carbon, and nitrogen is formed on the wafer 200 by performing acycle a predetermined number of times, the cycle including a process ofsupplying a specific element-containing gas to the wafers 200, a processof supplying a carbon-containing gas to the wafer 200, a process ofsupplying an oxidizing gas to the wafer 200, and a process of supplyinga nitriding gas to the wafer 200.

In addition, in the process of forming the thin film, the process ofsupplying the nitriding gas is performed before performing the processof supplying the specific element-containing gas, and the process ofsupplying the carbon-containing gas and the process of supplying theoxidizing gas are not performed until the process of supplying thespecific element-containing gas is performed after the process ofsupplying the nitriding gas is performed. Specifically, the process ofsupplying the nitriding gas is performed, and then a cycle including theprocess of supplying the specific element-containing gas, the process ofsupplying the carbon-containing gas, and the process of supplying theoxidizing gas, and the process of supplying the nitriding gas isperformed a predetermined number of times.

More specifically, the process of supplying the nitriding gas isperformed, and then the process of supplying the specificelement-containing gas, the process of supplying the carbon-containinggas, the process of supplying the oxidizing gas, and the process ofsupplying the nitriding gas are sequentially performed. The foursequentially performed processes are set as being included in one cycle,which is performed a predetermined number of times. The predeterminednumber of times may be a plurality of times.

Hereinafter, the first sequence will be described in detail. Here, anHCDS gas is used as the specific element-containing gas, a C₃H₆ gas isused as the carbon-containing gas, an O₂ gas is used as the oxidizinggas, and an NH₃ gas is used as the nitriding gas. The followingdescription will be made on an example that forms a silicon oxide carbonnitride film (SiOCN film) containing silicon, oxygen, carbon, andnitrogen on the wafer 200 in the film-forming sequence of FIG. 4A,namely, a film-forming sequence in which a process of supplying the NH₃gas is performed and then a cycle in which a process of supplying theHCDS gas, a process of supplying the C₃H₆ gas, a process of supplyingthe O₂ gas, and a process of supplying the NH₃ gas are sequentiallyperformed is performed a predetermined number of times.

In addition, when the term “wafer” is used herein, it may refer to “thewafer itself” or “the wafer and a stacked body (a collected body) ofpredetermined layers or films formed on the surface” (i.e., the waferincluding the predetermined layers or films formed on the surface may bereferred to as a wafer). In addition, the phrase “a surface of a wafer”as used herein may refer to “a surface (an exposed surface) of a waferitself” or “a surface of a predetermined layer or film formed on thewafer, namely, the uppermost surface of the wafer, which is a stackedbody.”

Accordingly, when “a predetermined gas is supplied to a wafer” iswritten herein, it may mean that “a predetermined gas is directlysupplied to a surface (exposed surface) of a wafer itself” or that “apredetermined gas is supplied to a layer or a film formed on a wafer,namely, on the uppermost surface of a wafer as a stacked body.” Also,when “a predetermined layer (of film) is formed on a wafer” is writtenherein, it may mean that “a predetermined layer (or film) is directlyformed on a surface (an exposed surface) of a wafer itself” or that “apredetermined layer (or film) is formed on a layer or a film formed on awafer, namely, on the uppermost surface of a wafer as a stacked body.”

Moreover, the term “substrate” as used herein may be synonymous with theterm “wafer”, and in this case, the terms “wafer” and “substrate” may beused interchangeably.

(Wafer Charge and Boat Load)

When the plurality of wafers 200 are charged on the boat 217 (wafercharging), as illustrated in FIG. 1, the boat 217 supporting theplurality of wafers 200 is raised by the boat elevator 115 to be loadedinto the processing chamber 201 (boat loading). In this state, the sealcap 219 seals the lower end of the reaction tube 203 via the O-ring 220.

(Pressure Adjustment and Temperature Adjustment)

The interior of the processing chamber 201 is vacuum-exhausted by thevacuum pump 246 to a desired pressure (vacuum level). Here, the pressurein the processing chamber 201 is measured by the pressure sensor 245,and the APC valve 244 is feedback-controlled based on the measuredpressure information (pressure adjustment). Also, the vacuum pump 246maintains a regular operation state at least until processing of thewafers 200 is terminated. Further, the processing chamber 201 is heatedby the heater 207 to a desired temperature. Here, an electricalconduction to the heater 207 is feedback-controlled based on thetemperature information detected by the temperature sensor 263 until theinterior of the processing chamber 201 reaches a desired temperaturedistribution (temperature adjustment). In addition, heating of theinterior of the processing chamber 201 by the heater 207 is continuouslyperformed at least until processing of the wafers 200 is terminated.Next, the boat 217 and the wafers 200 begin to be rotated by the rotarymechanism 267 (wafer rotation). Furthermore, the rotation of the boat217 and the wafers 200 by the rotary mechanism 267 is continuouslyperformed at least until processing of the wafers 200 is terminated.

(Process of Forming Silicon Oxycarbonitride Film)

Next, a surface modification step which will be described later isperformed, and then four steps which will be described later, namely,Steps 1 to 4, are sequentially performed.

[Surface Modification Step] (NH₃ Gas Supply)

The valve 243 d of the fourth gas supply pipe 232 d is opened to flowthe NH₃ gas in the fourth gas supply pipe 232 d. A flow rate of the NH₃gas flowing in the fourth gas supply pipe 232 d is regulated by the massflow controller 241 d. The flow rate-controlled NH₃ gas is supplied intothe processing chamber 201 through the gas supply holes 250 d of thefourth nozzle 249 d. At this time, the high-frequency power is notapplied between the first rod-shaped electrode 269 and the secondrod-shaped electrode 270. Thus, the NH₃ gas supplied into the bufferchamber 237 is activated by heat, supplied into the processing chamber201 through the gas supply holes 250 a, and exhausted through theexhaust pipe 231. At this time, the NH₃ gas activated by heat issupplied to the wafer 200. Also, at this time, by applying thehigh-frequency power between the first rod-shaped electrode 269 and thesecond rod-shaped electrode 270, the NH₃ gas supplied into the bufferchamber 237 may be activated by plasma and then supplied to the wafer200. In this case, the high-frequency power applied from thehigh-frequency power source 273 between the first rod-shaped electrode269 and the second rod-shaped electrode 270 is set to fall within arange of, for example, 50 to 1,000 W. Other processing conditions aresimilar to a processing condition (described later) in a case in whichthe NH₃ gas is activated by heat and supplied.

At the same time, the valve 243 h is opened to flow a N₂ gas into thefourth inert gas supply pipe 232 h. The N₂ gas flowing in the fourthinert gas supply pipe 232 h is supplied into the processing chamber 201through the buffer chamber 237 together with the NH₃ gas, and exhaustedthrough the exhaust pipe 231. At this time, in order to preventinfiltration of the NH₃ gas into the first nozzle 249 a, the secondnozzle 249 b, and the third nozzle 249 c, the valves 243 e, 243 f and243 g are opened to flow the N₂ gas into the first inert gas supply pipe232 e, the second inert gas supply pipe 232 f, and the third inert gassupply pipe 232 g. The N₂ gas is supplied into the processing chamber201 through the first gas supply pipe 232 a, the second gas supply pipe232 b, the third gas supply pipe 232 c, the first nozzle 249 a, thesecond nozzle 249 b, and the third nozzle 249 c, and exhausted throughthe exhaust pipe 231.

When flowing the NH₃ gas that is activated by heat, the APC valve 244 isappropriately adjusted to change the internal pressure of the processingchamber 201 to a pressure within a range of, for example, 1 to 6,000 Pa.A supply flow rate of the NH₃ gas controlled by the mass flow controller241 d is set to fall within a range of, for example, 100 to 10,000 sccm.Supply flow rates of the N₂ gas controlled by the mass flow controllers241 h, 241 e, 241 f and 241 g are set to fall within a range of, forexample, 100 to 10,000 sccm. Here, a partial pressure of the NH₃ gas inthe processing chamber 201 is set to fall within a range of, forexample, 0.01 to 5941 Pa. A time for supplying the NH₃ gas to the wafer200, namely, a gas supply time (irradiation time), is set to fall withina range of, for example, 1 to 600 seconds. Also, a time for supplyingthe NH₃ gas in the surface modification step may be, for example, set tobe longer than a time for supplying the NH₃ gas in a later-describedstep 4. Thus, surface modification (described later) may be sufficientlyperformed on the uppermost surface of the wafer 200 before forming afilm. In this case, a temperature of the heater 207 is set such that atemperature of the wafer 200 falls within a range of, for example, 250to 700 degrees C. or more specifically, for example 300 to 650 degreesC. Since the NH₃ gas has a high reaction temperature and is difficult toreact at the above-described wafer temperature, by setting the internalpressure of the processing chamber 201 to the above-described relativelyhigh pressure, it is possible to thermally activate the NH₃ gas. Also,when the NH₃ gas is activated by heat and supplied, a soft reaction canbe caused, and thus, the surface modification to be described later maybe softly performed.

The uppermost surface of the wafer 200 is modified (surfacemodification) by supplying the activated NH₃ gas to the uppermostsurface (base surface when forming the SiOCN film) of the wafer 200. Atthis time, for example, the uppermost surface of the wafer 200 may reactwith the activated NH₃ gas to be nitrided, and thus, a layer having Si—Nbonding, namely, a nitride layer (silicon nitride layer) containingsilicon (Si) and nitrogen (N) may be formed at the uppermost surface ofthe wafer 200. Also, for example, the NH₃ gas may be adsorbed onto theuppermost surface of the wafer 200, and thus, an adsorption layer of theNH₃ gas may be formed at the uppermost surface of the wafer 200. Inaddition, such reactions are performed at the same time, and the nitridelayer and the adsorption layer of the NH₃ gas may be formed at bothsides of the uppermost surface of the wafer 200, respectively.

The nitride layer includes a discontinuous layer in addition to acontinuous layer containing Si and Cl. That is, the nitride layerincludes a layer having a thickness of less than one atomic layerincluding Si—N bonding to several atomic layers. Also, the adsorptionlayer of the NH₃ gas includes a chemisorption layer in which gasmolecules of the NH₃ gas are discontinuous, in addition to achemisorption layer in which the gas molecules of the NH₃ gas arecontinuous. That is, the adsorption layer of the NH₃ gas includes achemisorption layer having a thickness of one molecular layer containingNH₃ gas molecules or less than one molecular layer. Also, the NH₃ gasmolecules constituting the adsorption layer of the NH₃ contain moleculesin which bonding of N and H is partially broken (N_(x)H_(y) molecules).That is, the adsorption layer of the NH₃ gas includes a chemisorptionlayer, in which the NH₃ gas molecules and/or the N_(x)H_(y) moleculesare continuous, or a chemisorption layer in which the NH₃ gas moleculesand/or the N_(x)H_(y) molecules are discontinuous. Also, a layer havinga thickness of less than one atomic layer refers to a discontinuouslyformed atomic layer, and a layer having a thickness of one atomic layerrefers to a continuously formed atomic layer. In addition, a layerhaving a thickness of less than one molecular layer refers to adiscontinuously formed molecular layer, and a layer having a thicknessof one molecular layer refers to a continuously formed molecular layer.

The uppermost surface of the wafer 200 after surface modification has asurface state in which it is easy for HCDS gas supplied inlater-described step 1 to be adsorbed onto the uppermost surface, and itis easy for Si to be deposited on the uppermost surface. That is, theNH₃ gas used in the surface modification step acts as an adsorption anddeposition facilitating gas that facilitates adsorption or deposition ofthe HCDS gas or Si onto the uppermost surface of the wafer 200.

(Residual Gas Removal)

Thereafter, the valve 243 d of the fourth gas supply pipe 232 d isclosed to stop the supply of the NH₃ gas. Here, the APC valve 244 of theexhaust pipe 231 is in an open state, and the interior of the processingchamber 201 is vacuum-exhausted by the vacuum pump 246 to removeunreacted NH₃ gas (or the NH₃ gas which remains after contributing tothe surface modification of the wafer 200) and reaction byproductsremaining in the processing chamber 201. Also, at this time, the valves243 h, 243 e, 243 f and 243 g are in an open state, and the supply ofthe N₂ gas into the processing chamber 201 is maintained. In this case,the unreacted NH₃ gas (or the NH₃ gas which remains after contributingto the surface modification of the wafer 200) and the reactionbyproducts remaining in the processing chamber 201 can be moreeffectively removed from the inside of the processing chamber 201.

Moreover, in this case, the gas remaining in the processing chamber 201may not be completely removed, and the interior of the processingchamber 201 may not be completely purged. When the gas remaining in theprocessing chamber 201 is very small in amount, there is no adverseeffect generated in Step 1 performed thereafter. Here, a flow rate ofthe N₂ gas supplied into the processing chamber 201 need not be a largeflow rate, and for example, approximately the same volume of the N₂ gasas the reaction tube 203 (processing chamber 201) may be supplied intothe processing chamber 201 to purge the interior of the processingchamber 201 such that there is no adverse effect generated in Step 1. Asdescribed above, as the interior of the processing chamber 201 is notcompletely purged, the purge time can be reduced to improve athroughput. In addition, consumption of the N₂ gas can be suppressed toa minimal necessity.

The nitriding gas may include a diazene (N₂H₂) gas, a hydrazine (N₂H₄)gas, an N₃H₈ gas, or the like, in addition to the ammonia (NH₃) gas. Theinert gas may include a rare gas such as an Ar gas, a He gas, a Ne gas,a Xe gas, or the like, in addition to the N₂ gas.

[Step 1] (HCDS Gas Supply)

After the surface modification step is terminated and the residual gasin the processing chamber 201 is removed, the valve 243 a of the firstgas supply pipe 232 a is opened to flow the HCDS gas in the first gassupply pipe 232 a. A flow rate of the HCDS gas flowing in the first gassupply pipe 232 a is regulated by the mass flow controller 241 a. Theflow rate-regulated HCDS gas is supplied into the processing chamber 201through the gas supply holes 250 a of the first nozzle 249 a, andexhausted through the exhaust pipe 231. At this time, the HCDS gas issupplied to the wafer 200.

At the same time, the valve 243 e is opened to flow the inert gas suchas the N₂ gas into the first inert gas supply pipe 232 e. A flow rate ofthe N₂ gas flowing in the first inert gas supply pipe 232 e is regulatedby the mass flow controller 241 e. The flow rate-regulated N₂ gas issupplied into the processing chamber 201 with the HCDS gas, andexhausted through the exhaust pipe 231. In addition, here, in order toprevent infiltration of the HCDS gas into the second nozzle 249 b, thethird nozzle 249 c, the fourth nozzle 249 d, and the buffer chamber 237,the valves 243 f, 243 g and 243 h are opened to flow the N₂ gas into thesecond inert gas supply pipe 232 f, the third inert gas supply pipe 232g, and the fourth inert gas supply pipe 232 h. The N₂ gas is suppliedinto the processing chamber 201 through the second gas supply pipe 232b, the third gas supply pipe 232 c, the fourth gas supply pipe 232 d,the second nozzle 249 b, the third nozzle 249 c, the fourth nozzle 249d, and the buffer chamber 237, and exhausted through the exhaust pipe231.

At this time, the APC valve 244 is appropriately adjusted to change theinternal pressure of the processing chamber 201 to fall within a rangeof, for example, 1 to 13,300 Pa, and more specifically, for example 20to 1,330 Pa. A supply flow rate of the HCDS gas controlled by the massflow controller 241 a is set to fall within a range of, for example, 1to 1,000 sccm. Supply flow rates of the N₂ gas controlled by the massflow controllers 241 e, 241 f, 241 g and 241 h are set to fall within arange of, for example, 100 to 10,000 sccm. A time of supplying the HCDSgas to the wafer 200, namely, a gas supply time (irradiation time), isset to fall within a range of, for example, 1 to 200 seconds. This rangemay be more specifically, for example, 1 to 120 seconds or 1 to 60seconds. At this time, a temperature of the heater 207 is set such thata temperature of the wafer 200 is set to fall within a range of, forexample, 250 to 700 degrees C. This range may be more specifically, forexample, 300 to 650 degrees C. or 350 to 600 degrees C. Also, when thetemperature of the wafer 200 is less than 250 degrees C., it becomesdifficult for the HCDS gas to be adsorbed onto the wafer 200, and forthis reason, a practical deposition rate cannot be obtained. Thisproblem can be solved by setting the temperature of the wafer 200 to 250degrees C. or more. Also, the HCDS can be more sufficiently adsorbedonto the wafer 200 by setting the temperature of the wafer 200 to 300degrees C. or more, and a more sufficient deposition rate can beobtained. Also, when the temperature of the wafer 200 exceeds 700degrees C., a CVD reaction is strengthened (a gaseous reaction becomesdominant), and thus, a film thickness uniformity may be easilydeteriorated to make it difficult to control the film thicknessuniformity. By regulating the temperature of the wafer to 700 degrees C.or less, deterioration of the film thickness uniformity can beprevented, and thus, it is possible to control the film thicknessuniformity. In particular, when a surface reaction becomes dominant byregulating the temperature of the wafer 200 to 650 degrees C. or less,the film thickness uniformity can be easily secured, and thus, itbecomes easy to control the film thickness uniformity. Accordingly, thetemperature of the wafer 200 may be set to fall within a range of 250 to700 degrees C., for example, within 300 to 650 degrees C.

By supplying the HCDS gas to the wafer 200, a silicon-containing layerhaving a thickness of about less than one atomic layer to several atomiclayers is formed as a first layer on the uppermost surface of the wafer200 which has been modified by the NH₃ gas in the surface modificationstep. The silicon-containing layer may be an adsorption layer of theHCDS gas, a silicon layer (Si layer), or both of these. However, thesilicon-containing layer may, for example, be a layer containing silicon(Si) and chlorine (Cl).

Here, the silicon layer is a generic name including a discontinuouslayer in addition to a continuous layer formed of silicon (Si), or asilicon thin film formed by overlapping them. Also, a continuous layerformed of Si may be referred to as the silicon thin film. In addition,Si constituting the silicon layer includes Si in which bonding to Cl isnot completely broken.

Moreover, the adsorption layer of the HCDS gas includes a chemisorptionlayer in which gas molecules of the HCDS gas are discontinuous, inaddition to the chemisorption layer in which the gas molecules of theHCDS gas are continuous. That is, the adsorption layer of the HCDS gasincludes a chemisorption layer having a thickness of one molecular layercontaining HCDS molecules or less than one molecular layer. Also, HCDS(Si₂Cl₆) molecules constituting the adsorption layer of the HCDS gascontains molecules in which bonding of Si and Cl is partially broken(Si_(x)Cl_(y) molecules). That is, the adsorption layer of the HCDSincludes a chemisorption layer in which Si₂Cl₆ molecules and/orSi_(x)Cl_(y) molecules are continuous, or a chemisorption layer in whichSi₂Cl₆ molecules and/or Si_(x)Cl_(y) molecules are discontinuous. Also,a layer having a thickness of less than one atomic layer refers to adiscontinuously formed atomic layer, and a layer having a thickness ofone atomic layer refers to a continuously formed atomic layer. Inaddition, a layer having a thickness of less than one molecular layerrefers to a discontinuously formed molecular layer, and a layer having athickness of one molecular layer refers to a continuously formedmolecular layer.

Under conditions in which the HCDS gas is autolyzed (pyrolyzed), i.e.,under conditions in which a pyrolysis reaction of the HCDS occurs, thesilicon layer containing Cl is formed by depositing Si on the wafer 200.Under conditions in which the HCDS gas is not autolyzed (pyrolyzed),namely, under conditions in which a pyrolysis reaction of the HCDS doesnot occur, the adsorption layer of the HCDS gas is formed by adsorbingthe HCDS gas onto the wafer 200. In addition, formation of theadsorption layer of the HCDS gas on the wafer 200 can increase thefilm-forming rate more than formation of the silicon layer containing Clon the wafer 200.

When the thickness of the silicon-containing layer formed on the wafer200 exceeds several atomic layers, an effect of modification in Steps 3and 4 described later is not applied to the entire silicon-containinglayer. In addition, a minimum value of the thickness of thesilicon-containing layer that can be formed on the wafer 200 is lessthan one atomic layer. Accordingly, the thickness of thesilicon-containing layer may be less than one atomic layer to severalatomic layers. In addition, as the thickness of the silicon-containinglayer is one atomic layer or less, namely, one atomic layer or less thanone atomic layer, an effect of the modification reaction in Steps 3 and4 described later can be relatively increased, and a time required forthe modification reaction in Steps 3 and 4 can be reduced. A time forforming the silicon-containing layer in Step 1 can be reduced. As aresult, a processing time per one cycle can be reduced, and a totalprocessing time can also be reduced. That is, the film-forming rate canalso be increased. In addition, as the thickness of thesilicon-containing layer is one atomic layer or less, a controllabilityof the film thickness uniformity can also be increased.

(Residual Gas Removal)

After the silicon-containing layer is formed, the valve 243 a of thefirst gas supply pipe 232 a is closed to stop the supply of the HCDSgas. At this time, the APC valve 244 of the exhaust pipe 231 is in anopen state, and the interior of the processing chamber 201 isvacuum-exhausted by the vacuum pump 246 to remove unreacted HCDS gas (orthe HCDS gas which remains after contributing to the formation of thesilicon-containing layer) or reaction byproducts remaining in theprocessing chamber 201. Also, at this time, the valves 243 e, 243 f, 243g and 243 h are in an open state, and maintain the supply of the N₂ gas(inert gas) into the processing chamber 201. The N₂ gas acts as a purgegas, and thus the unreacted HCDS gas (or the HCDS gas which remainsafter contributing to the formation of the silicon-containing layer) orreaction byproducts remaining in the processing chamber 201, can be moreeffectively removed from the inside of the processing chamber 201.

Moreover, in this case, the gas remaining in the processing chamber 201may not be completely removed, and the interior of the processingchamber 201 may not be completely purged. When the gas remaining in theprocessing chamber 201 is very small in amount, there is no adverseeffect generated in Step 2 performed thereafter. Here, a flow rate ofthe N₂ gas supplied into the processing chamber 201 need not be a largeflow rate, and for example, approximately the same volume of the N₂ gasas the reaction tube 203 (processing chamber 201) may be supplied toperform the purge such that there is no adverse effect generated in Step2. As described above, as the interior of the processing chamber 201 isnot completely purged, the purge time can be reduced to improve athroughput. In addition, consumption of the N₂ gas can be suppressed toa minimal necessity.

The silicon-containing gas may include an inorganic raw material gassuch as a tetrachlorosilane, namely, a silicon tetrachloride (SiCl₄,abbreviation: STC) gas, a trichlorosilane (SiHCl₃, abbreviation: TCS)gas, a dichlorosilane (SiH₂Cl₂, abbreviation: DCS) gas, amonochlorosilane (SiH₃Cl, abbreviation: MCS) gas, a monosilane (SiH₄)gas, or the like, in addition to a hexachlorodisilane (Si₂Cl₆,abbreviation: HCDS) gas, or use an organic raw material gas such as anaminosilane-based tetrakis(dimethylamino)silane (Si[N(CH₃)₂]₄,abbreviation: 4DMAS) gas, a tris(dimethylamino)silane (Si[N(CH₃)₂]₃H,abbreviation: 3DMAS) gas, a bis(diethylamido)silane (Si[N(C₂H₅)₂]₂H₂,abbreviation: 2DEAS) gas, or a bis tertiary butyl amino silane(SiH₂[NH(C₄H₉)]2, abbreviation: BTBAS) gas, or the like. The inert gasmay include a rare gas such as an Ar gas, a He gas, a Ne gas, a Xe gas,or the like, in addition to the N₂ gas.

[Step 2] (C₃H₆ Gas Supply)

After Step 1 is terminated and the residual gas in the processingchamber 201 is removed, the valve 243 d of the second gas supply pipe232 b is opened to flow the C₃H₆ gas in the second gas supply pipe 232b. A flow rate of the C₃H₆ gas flowing in the second gas supply pipe 232b is regulated by the mass flow controller 241 b. The flowrate-regulated C₃H₆ gas is supplied into the processing chamber 201through the gas supply holes 250 b of the second nozzle 249 b. The C₃H₆gas supplied into the processing chamber 201 is activated by heat, andexhausted through the exhaust pipe 231. At this time, the C₃H₆ gasactivated by heat is supplied to the wafer 200.

At the same time, the valve 243 f is opened to flow the N₂ gas into thesecond inert gas supply pipe 232 f. The N₂ gas flowing in the secondinert gas supply pipe 232 f is supplied into the processing chamber 201together with the C₃H₆ gas, and exhausted through the exhaust pipe 231.Also, at this time, in order to prevent infiltration of the C₃H₆ gasinto the first nozzle 249 a, the third nozzle 249 c, the fourth nozzle249 d, and the buffer chamber 237, the valves 243 e, 243 g and 243 h areopened to flow the N₂ gas into the first inert gas supply pipe 232 e,the third inert gas supply pipe 232 g, and the fourth inert gas supplypipe 232 h. The N₂ gas is supplied into the processing chamber 201through the first gas supply pipe 232 a, the third gas supply pipe 232c, the fourth gas supply pipe 232 d, the first nozzle 249 a, the thirdnozzle 249 c, the fourth nozzle 249 d, and the buffer chamber 237, andexhausted through the exhaust pipe 231.

At this time, the APC valve 244 is appropriately adjusted to change theinternal pressure of the processing chamber 201 to fall within a rangeof, for example, 1 to 6,000 Pa. A supply flow rate of the C₃H₆ gascontrolled by the mass flow controller 241 b is set to fall within arange of, for example, 100 to 10,000 sccm. Supply flow rates of the N₂gas controlled by the mass flow controllers 241 f, 241 e, 241 g and 241h are set to fall within a range of, for example, 100 to 10,000 sccm.Here, a partial pressure of the C₃H₆ gas in the processing chamber 201is set to fall within a range of, for example, 0.01 to 5941 Pa. A timefor supplying the C₃H₆ gas to the wafer 200, namely, a gas supply time(irradiation time), is set to fall within a range of, for example, 1 to200 seconds. This range may be more specifically, for example, 1 to 120seconds or 1 to 60 seconds. In this case, similarly to Step 1, atemperature of the heater 207 is set such that a temperature of thewafer 200 falls within a range of, for example, 250 to 700 degrees C.,or more specifically, for example, 300 to 650 degrees C. Also, when theC₃H₆ gas is activated by heat and supplied, a soft reaction can becaused, and thus, it becomes easy to form a carbon-containing layerdescribed later.

At this time, the gas flowing into the processing chamber 201 is thethermally activated C₃H₆ gas, and the HCDS gas does not flow into theprocessing chamber 201. Accordingly, the C₃H₆ gas does not cause agaseous reaction, and the activated C₃H₆ gas is supplied to the wafer200, and a carbon-containing layer having a thickness of less than oneatomic layer, namely, a discontinuous carbon-containing layer is formedon the silicon-containing layer as the first layer formed on the wafer200 in Step 1. That is, a second layer containing silicon and carbon,namely, a layer in which a carbon-containing layer is formed on thesilicon-containing layer, is formed. Also, depending on a condition, theC₃H₆ gas may react with a portion of the silicon-containing layer, andthus, the silicon-containing layer is modified (carbonized) to form thesecond layer containing silicon and carbon.

The carbon-containing layer formed on the silicon-containing layer maybe a carbon layer (C layer), or may be an adsorption layer of acarbon-containing gas (C₃H₆ gas), namely, a chemisorption layer of amaterial (C_(x)H_(y)) into which the C₃H₆ gas is decomposed. Here, thecarbon layer needs be a discontinuous layer formed of carbon. Also, thechemisorption layer of C_(x)H_(y) needs be a discontinuous chemisorptionlayer of C_(x)H_(y) molecules. Also, when the carbon-containing layerformed on the silicon-containing layer is a continuous layer, forexample, when a continuous chemisorption layer of C_(x)H_(y) is formedon the silicon-containing layer by changing an adsorption state on asilicon-containing layer of C_(x)H_(y) to a saturation state, a surfaceof the silicon-containing layer is overall covered by the chemisorptionlayer of C_(x)H_(y). In this case, there is no silicon on a surface ofthe second layer, and thus, it can become possible to cause an oxidationreaction of the second layer in Step 3 described later or cause anitridation reaction of a third layer in Step 4 described later. Underthe above-described processing conditions, nitrogen or oxygen is bondedto silicon, but it is difficult to bond to carbon. For this reason, inorder to cause a desired oxidation reaction or nitridation reaction, anadsorption state on the silicon-containing layer of C_(x)H_(y) ischanged to an unsaturation state, and it is required to expose siliconto the surface of the second layer.

The processing conditions in Step 2 are set to the above-describedprocessing conditions in order to change the adsorption state on thesilicon-containing layer of C_(x)H_(y) to the unsaturation state, but bysetting the processing conditions in Step 2 to the following processingconditions, it becomes easy to change the adsorption state on thesilicon-containing layer of C_(x)H_(y) to the unsaturation state.

Wafer temperature: 500 to 650 degrees C.

Pressure in processing chamber: 133 to 5,332 Pa

Partial pressure of C₃H₆ gas: 33 to 5,177 Pa

Supply flow rate of C₃H₆ gas: 1,000 to 10,000 sccm

Supply flow rate of N₂ gas: 300 to 3,000 sccm

C₃H₆ gas supply time: 6 to 200 seconds

(Residual Gas Removal)

After the second layer is formed, the valve 243 b of the second gassupply pipe 232 b is closed to stop the supply of the C₃H₆ gas. At thistime, the interior of the processing chamber 201 is vacuum-exhausted bythe vacuum pump 246 in a state in which the APC valve 244 of the exhaustpipe 231 is open, and unreacted C₃H₆ gas (or the C₃H₆ gas which remainsafter contributing to the formation of the second layer) or reactionbyproducts remaining in the processing chamber 201 is removed from theprocessing chamber 201. Also, at this time, the valves 243 f, 243 e, 243g and 243 f are in an open state, and the supply of the N₂ gas (inertgas) into the processing chamber 201 is maintained. The N₂ gas acts as apurge gas, and thus the unreacted C₃H₆ gas (or the C₃H₆ gas whichremains after contributing to the formation of the second layer) orreaction byproducts remaining in the processing chamber 201 can be moreeffectively removed from the processing chamber 201.

Moreover, in this case, the gas remaining in the processing chamber 201may not be completely removed, and the interior of the processingchamber 201 may not be completely purged. When the amount of gasremaining in the processing chamber 201 is very small, there is noadverse effect generated in Step 3 performed thereafter. Here, the flowrate of the N₂ gas supplied into the processing chamber 201 need not bea large flow rate, and for example, approximately the same volume of theN₂ gas as the reaction tube 203 (the processing chamber 201) may besupplied to perform the purge such that there is no adverse effectgenerated in Step 2. As described above, as the interior of theprocessing chamber 201 is not completely purged, the purge time can bereduced to improve a throughput. In addition, consumption of the N₂ gascan also be suppressed to a minimal necessity.

The carbon-containing gas may include a hydrocarbon-based gas such as anacetylene (C₂H₂) gas, an ethylene (C₂H₄) gas, or the like, in additionto the propylene (C₃H₆) gas.

[Step 3] (O₂ Gas Supply)

After Step 2 is terminated and the residual gas in the processingchamber 201 is removed, the valve 243 c of the third gas supply pipe 232c is opened to flow the O₂ gas in the third gas supply pipe 232 c. Aflow rate of the O₂ gas flowing in the third gas supply pipe 232 c isregulated by the mass flow controller 241 c. The flow rate-regulated O₂gas is supplied into the processing chamber 201 through the gas supplyholes 250 c of the third nozzle 249 c, and exhausted through the exhaustpipe 231. At this time, the O₂ gas is supplied to the wafer 200.

At the same time, the valve 243 g is opened to flow the N₂ gas into thethird inert gas supply pipe 232 g. The N₂ gas flowing in the third inertgas supply pipe 232 g is supplied into the processing chamber 201together with the O₂ gas, and exhausted through the exhaust pipe 231.Also, at this time, in order to prevent infiltration of the O₂ gas intothe first nozzle 249 a, the second nozzle 249 b, the fourth nozzle 249d, and the buffer chamber 237, the valves 243 e, 243 f and 243 h areopened to flow the N₂ gas into the first inert gas supply pipe 232 e,the second inert gas supply pipe 232 f, and the fourth inert gas supplypipe 232 h. The N₂ gas is supplied into the processing chamber 201through the first gas supply pipe 232 a, the second gas supply pipe 232b, the fourth gas supply pipe 232 d, the first nozzle 249 a, the secondnozzle 249 b, the fourth nozzle 249 d, and the buffer chamber 237, andexhausted through the exhaust pipe 231.

At this time, the APC valve 244 is appropriately adjusted to change theinternal pressure of the processing chamber 201 to fall within a rangeof, for example, 1 to 6,000 Pa. A supply flow rate of the O₂ gascontrolled by the mass flow controller 241 c is set to fall within arange of, for example, 100 to 10,000 sccm. Supply flow rates of the N₂gas controlled by the mass flow controllers 241 g, 241 e, 241 f and 241h are set to fall within a range of, for example, 100 to 10,000 sccm. Inthis case, a partial pressure of the O₂ gas in the processing chamber201 is set to fall within a range of, for example, 0.01 to 5941 Pa. Atime for supplying the O₂ gas to the wafer 200, namely, a gas supplytime (irradiation time), is set to fall within a range of, for example,1 to 200 seconds. This range may include more specifically, for example,1 to 120 seconds or 1 to 60 seconds. In this case, similarly to Steps 1and 2, a temperature of the heater 207 is set such that a temperature ofthe wafer 200 falls within a range of, for example, 250 to 700 degreesC., or more specifically, for example, 300 to 650 degrees C. The O₂ gasis thermally activated under the above-described conditions. Also, whenthe O₂ gas is activated by heat and supplied, a soft reaction can becaused, and thus, oxidation described later can be softly performed.

In this case, the gas flowing into the processing chamber 201 is thethermally activated O₂ gas, and neither the HCDS gas nor the C₃H₆ gasflows in the processing chamber 201. Accordingly, the O₂ gas does notcause a gaseous reaction, and the activated O₂ gas is supplied to thewafer 200 and reacts with at least a portion of the second layer (layerin which the carbon-containing layer is formed on the silicon-containinglayer) containing silicon and carbon which has been formed on the wafer200 in Step 2. Therefore, the second layer is thermally oxidized bynon-plasma, and thereby changed (modified) into the third layercontaining silicon, oxygen, and carbon, namely, to a silicon oxidecarbon layer (SiOC layer).

In this case, the oxidation reaction of the second layer is notsaturated. For example, when a silicon-containing layer having athickness of several atomic layers is formed in Step 1 and acarbon-containing layer having a thickness of one atomic layer is formedin Step 2, at least a portion of a surface layer thereof (one atomiclayer of a surface) is oxidized. In this case, in order for all of thesecond layer not to be oxidized, the oxidation is performed under acondition in which the oxidation reaction of the second layer isunsaturated. Also, depending on a condition, some layers may be oxidizeddownward from the surface layer of the second layer, but when only thesurface layer is oxidized, a controllability of a composition ratio ofthe SiOCN film can be enhanced. In addition, for example, when asilicon-containing layer having a thickness of one atomic layer or lessthan one atomic layer is formed in Step 1 and a carbon-containing layerhaving a thickness of less than one atomic layer is formed in Step 2, aportion of a surface layer thereof is also oxidized. Even in this case,in order for all of the second layer not to be oxidized, the oxidationis performed under a condition in which the oxidation reaction of thesecond layer is unsaturated.

In addition, the processing conditions in Step 3 are set to theabove-described processing conditions in order for the oxidationreaction of the second layer to be unsaturated, but by setting theprocessing conditions in Step 3 to the following processing conditions,it becomes easy for the oxidation reaction of the second layer to beunsaturated.

Wafer temperature: 500 to 650 degrees C.

Pressure in processing chamber: 133 to 5,332 Pa

Partial pressure of O₂ gas: 12 to 5,030 Pa

Supply flow rate of O₂ gas: 1,000 to 5,000 sccm

Supply flow rate of N₂ gas: 300 to 10,000 sccm

O₂ gas supply time: 6 to 200 seconds

Moreover, in this case, as the above-described processing conditions areadjusted to increase a dilution rate of the O₂ gas (or lower aconcentration of the O₂ gas), to shorten the supply time of the O₂ gas,or to lower the partial pressure of the O₂ gas, oxidizing power in Step3 can be appropriately reduced, and thus, it becomes easier for theoxidation reaction of the second layer to be unsaturated. Thefilm-forming sequence of FIG. 4A shows a state in which when a supplyflow rate of the N₂ gas in Step 3 is higher than a supply flow rate ofthe N₂ gas in other steps, the partial pressure of O₂ gas is lowered,and oxidizing power is weakened.

In an oxidizing process, by weakening the oxidizing power in Step 3, itbecomes easy to prevent carbon (C) from desorbing from inside the secondlayer. Since Si—C bonding has bonding energy higher than Si—O bonding,the Si—C bonding can be broken when Si—O bonding is formed, but byappropriately weakening the oxidizing power in Step 3, the Si—C bondingcan be prevented from being broken when the Si—O bonding is formed inthe second layer, and thus C that is decoupled from Si can be easilyprevented from desorbing from the second layer.

In addition, the oxidizing power in Step 3 is weakened, therebymaintaining a state in which Si is exposed to the second layer afteroxidation, namely, the uppermost surface of the third layer. Bymaintaining the state in which Si is exposed to the uppermost surface ofthe third layer, it becomes easy to nitride the uppermost surface of thethird layer in Step 4 described later. For example, when Si—O bonding orSi—C bonding is formed all over the uppermost surface of the third layerand Si is not exposed to the uppermost surface, it is difficult to formSi—N bonding under later-described conditions of Step 4. However, underthe state in which Si is exposed to the uppermost surface of the thirdlayer is maintained, namely, Si that is able to bond to N under thelater-described conditions of Step 4 is provided at the uppermostsurface of the third layer, it becomes easy to form Si—N bonding.

(Residual Gas Removal)

After the third layer is formed, the valve 243 c of the third gas supplypipe 232 c is closed to stop the supply of the O₂ gas. At this time, theAPC valve 244 of the exhaust pipe 231 is in an open state, and theinterior of the processing chamber 201 is vacuum-exhausted by the vacuumpump 246 to remove unreacted O₂ gas (or the O₂ gas which remains aftercontributing to the formation of the third layer) or reaction byproductsremaining in the processing chamber 201. Also, at this time, the valves243 g, 243 e, 243 f and 243 h are in an open state, and the supply ofthe N₂ gas (inert gas) into the processing chamber 201 is maintained.The N₂ gas acts as a purge gas, and thus the unreacted O₂ gas (or the O₂gas which remains after contributing to the formation of the thirdlayer) or reaction byproducts remaining in the processing chamber 201can be more effectively removed from the inside of the processingchamber 201.

Moreover, in this case, the gas remaining in the processing chamber 201may not be completely removed, and the interior of the processingchamber 201 may not be completely purged. When the gas remaining in theprocessing chamber 201 is very small in amount, there is no adverseeffect generated in Step 4 performed thereafter. Here, a flow rate ofthe N₂ gas supplied into the processing chamber 201 need not be a largeflow rate, and for example, approximately the same volume of the N₂ gasas the reaction tube 203 (processing chamber 201) may be supplied toperform the purge such that there is no adverse effect generated in Step4. As described above, as the interior of the processing chamber 201 isnot completely purged, the purge time can be reduced to improve athroughput. In addition, consumption of the N₂ gas can be suppressed toa minimal necessity.

An oxidizing gas may include a water vapor (H₂O) gas, a nitric oxide(NO) gas, a nitrous oxide (N₂O) gas, a nitrogen dioxide (NO₂) gas, acarbon monoxide (CO) gas, a carbon dioxide (CO₂) gas, an ozone (O₃) gas,a hydrogen (H₂) gas+an O₂ gas, a H₂ gas+an O₃ gas, or the like, inaddition to the oxygen (O₂) gas.

[Step 4] (NH₃ Gas Supply)

After Step 3 is terminated and the residual gas in the processingchamber 201 is removed, the NH₃ gas activated by heat is supplied to thewafer 200. In this case, a processing condition and a processingsequence are the almost same as a processing condition and a processingsequence in supplying the NH₃ gas in the above-described surfacemodification step. However, a time for supplying the NH₃ gas to thewafer 200, namely, a gas supply time (irradiation time), is set to fallwithin a range of, for example, 1 to 200 seconds. This range may be morespecifically, for example, 1 to 120 seconds or 1 to 60 seconds. Also,even in Step 4, the NH₃ gas is activated by heat and supplied. When theNH₃ gas is activated by heat and supplied, a soft reaction can becaused, and thus, nitridation described later can be softly performed.However, similarly to the above-described surface modification step, theNH₃ gas may be activated by plasma and supplied.

In this case, the gas flowing into the processing chamber 201 is thethermally activated NH₃ gas, and any of the HCDS gas, the C₃H₆ gas, theO₂ gas does not flow in the processing chamber 201. Accordingly, the NH₃gas does not cause a gaseous reaction, and the activated NH₃ gas issupplied to the wafer 200 and reacts with at least a portion of a layer(which is the third layer formed on the wafer 200 on Step 3) containingsilicon, oxygen, and carbon. Therefore, the third layer is thermallynitrided by non-plasma, and thereby changed (modified) to a fourth layercontaining silicon, oxygen, carbon, and nitrogen, namely, to a siliconoxide carbon nitride layer (SiOCN layer).

Moreover, the uppermost surface of the third layer is modified bysupplying the activated NH₃ gas to the wafer 200 (surface modification).At this time, for example, the uppermost surface of the third layerreacts with the activated NH₃ gas to be nitrided, and thus a layerhaving Si—N bonding, namely, a nitride layer (silicon nitride layer)containing Si and N, may be formed at the uppermost surface of the thirdlayer, namely, the uppermost layer of the fourth layer. Also, the NH₃gas is adsorbed onto the uppermost surface of the third layer, and thusan adsorption layer of the NH₃ gas may be formed at the uppermostsurface of the third layer, namely, the uppermost layer of the fourthlayer. In addition, such reactions may be caused at the same time, andthe nitride layer and the adsorption layer of the NH₃ gas may berespectively formed at both sides of the uppermost surface of the wafer200, namely, the uppermost layer of the fourth layer.

The third layer after surface modification, namely, the uppermostsurface of the fourth layer, has a surface state in which the HCDS gassupplied in subsequent Step 1 is easily adsorbed and Si is easilydeposited. That is, the NH₃ gas used in Step 4 acts as an adsorption anddeposition facilitating gas that facilitates adsorption or deposition ofthe HCDS gas or Si onto the uppermost surface of the wafer 200(uppermost surface of the fourth layer) in a next cycle.

Moreover, in this case, the nitridation reaction of the third layer isnot saturated. For example, when the third layer having a thickness ofseveral atomic layers in Steps 1 to 4, at least a portion of a surfacelayer thereof (one atomic layer of a surface) is nitrided. In this case,in order for all of the third layer not to be nitrided, the nitridationis performed under a condition in which the nitridation reaction of thethird layer is unsaturated. Also, depending on a condition, some layersmay be nitrided downward from the surface layer of the third layer, butwhen only the surface layer is nitrided, a controllability of thecomposition ratio of the SiOCN film can be enhanced. In addition, forexample, even when the third layer having a thickness of one atomiclayer or less than one atomic layer in Steps 1 to 3, a portion of thesurface layer is also nitrided. Even in this case, in order for all ofthe third layer not to be nitrided, the nitridation is performed under acondition in which the nitridation reaction of the third layer isunsaturated.

In addition, the processing conditions in Step 4 are set to theabove-described processing conditions in order for the nitridationreaction of the third layer to be unsaturated, but by setting theprocessing conditions in Step 4 to the following processing conditions,it becomes easy for the nitridation reaction of the third layer to beunsaturated.

Wafer temperature: 500 to 650 degrees C.

Pressure in processing chamber: 133 to 5,332 Pa

Partial pressure of NH₃ gas: 33 to 5,030 Pa

Supply flow rate of NH₃ gas: 1,000 to 5,000 sccm

Supply flow rate of N₂ gas: 300 to 3,000 sccm

NH₃ gas supply time: 6 to 200 seconds

(Residual Gas Removal)

After the fourth layer is formed, the interior of the processing chamber201 is vacuum-exhausted by the vacuum pump 246 to remove unreacted NH₃gas (or the NH₃ gas which remains after contributing to the formation ofthe fourth layer) or reaction byproducts remaining in the processingchamber 201. In this case, a processing condition and a processingsequence are the same as a processing condition and a processingsequence in removing the residual gas in the above-described surfacemodification step.

A nitriding gas, similarly to the surface modification step, may includea diazene (N₂H₂) gas, a hydrazine (N₂H₄) gas, an N₃H₈ gas, or the like,in addition to the ammonia (NH₃) gas.

The above-described Steps 1 to 4 may be set as being included in onecycle, and by performing the cycle one or more times (i.e.,predetermined number of times), a thin film (i.e., a siliconoxycarbonitride film (SiOCN film)) containing silicon, oxygen, carbon,and nitrogen and having a predetermined film thickness may be formed onthe wafer 200. Also, the above-described cycle may be performed aplurality of times. In this case, a ratio of element components of theSiOCN layer, namely, a ratio of a silicon component, an oxygencomponent, a carbon component, and a nitrogen component, namely, asilicon concentration, an oxygen concentration, a carbon concentration,and a nitrogen concentration, may be regulated by controlling aprocessing condition such as the internal pressure of the processingchamber 201, the gas supply time, or the like in each step, therebycontrolling a composition ratio of the SiOCN film. Also, when the cycleis performed a plurality of times, the phrase “a predetermined gas issupplied to the wafer 200” in each step after at least two cycles means“a predetermined gas is supplied to a layer formed on the wafer 200,namely, the uppermost surface of the wafer 200, which is a stackedbody,” and the phrase “a predetermined layer is formed on the wafer 200”means “a predetermined layer is formed on a layer formed on the wafer200, namely, the uppermost surface of the wafer 200, which is a stackedbody.” In addition, the above-described matters are similar in otherfilm-forming sequences or modification examples described later.

(Purge and Return to Atmospheric Pressure)

When a film-forming process of forming the SiOCN film having apredetermined film thickness and a predetermined composition isperformed, the inert gas such as the N₂ gas is supplied into theprocessing chamber 201 and exhausted, and the interior of the processingchamber 201 is purged with the inert gas (purge). Thereafter, anatmosphere in the processing chamber 201 is substituted with the inertgas (inert gas substitution), and the pressure in the processing chamber201 returns to the atmospheric pressure (return to atmosphericpressure).

(Boat Unload and Wafer Discharge)

Thereafter, the seal cap 219 is lowered by the boat elevator 115 to openthe lower end of the reaction tube 203, and the processed wafer 200supported by the boat 217 is unloaded to the outside of the reactiontube 203 through the lower end of the reaction tube 203 (boat unload).Then, the processed wafer 200 is discharged from the boat 217 (waferdischarge).

(Second Sequence)

Next, a second sequence will be described.

FIG. 5A is a timing diagram illustrating a gas supply timing in thesecond sequence, according to some embodiments.

In the second sequence described above, a cycle including a process ofsupplying a nitriding gas, a process of supplying a specificelement-containing gas, a process of supplying a carbon-containing gas,and a process of supplying an oxidizing gas is performed a predeterminednumber of times, and then a process of supplying the nitriding gas isperformed. This differs from the above-described first sequence.

More specifically, the process of supplying the nitriding gas, theprocess of supplying the specific element-containing gas, the process ofsupplying the carbon-containing gas, and the process of supplying theoxidizing gas are sequentially performed. The four sequentiallyperformed processes are set as being included in one cycle. The onecycle is performed a predetermined number of times, for example aplurality of times, and then the process of supplying the nitriding gasis performed.

That is, the process of supplying the nitriding gas is performed beforeperforming the process of supplying the specific element-containing gas.The process of supplying the carbon-containing gas and the process ofsupplying the oxidizing gas are not performed until the process ofsupplying the specific element-containing gas is performed after theprocess of supplying the nitriding gas is performed. This is similar tothe above-described first sequence.

Hereinafter, the second sequence will be described in detail. Here, theHCDS gas is used as the specific element-containing gas, the C₃H₆ gas isused as the carbon-containing gas, the O₂ gas is used as the oxidizinggas, and the NH₃ gas is used as the nitriding gas. The followingdescription is made on an example that forms a silicon oxide carbonnitride film (SiOCN film) containing silicon, oxygen, carbon, andnitrogen on the wafer 200 in the film-forming sequence of FIG. 5A,namely, the film-forming sequence in which the cycle, in which theprocess of supplying the NH₃ gas, the process of supplying the HCDS gas,the process of supplying the C₃H₆ gas, and the process of supplying theO₂ gas are sequentially performed, is performed a predetermined numberof times, and then the process of supplying the NH₃ gas is performed.

(Wafer Charge and Wafer Rotate)

Charging of a wafer, loading of a boat, regulating of a pressure,regulating of a temperature, and rotating of the wafer are performedsimilarly to the first sequence.

[Process of Forming Silicon Oxide Carbon Nitride Film]

Four steps described later, namely, Steps 1 to 4 are set as beingincluded in one cycle. The one cycle is performed one or more times, andthen nitridation step described later is performed.

[Step 1]

Step 1 is performed similarly to the surface modification step or Step 4of the first sequence. The processing conditions in Step 1 are similarto processing conditions in the surface modification step or Step 4 ofthe first sequence.

Moreover, a reaction caused, a layer formed, etc. in Step 1 in the firstcycle are similar to those in the surface modification step of the firstsequence. That is, by supplying the activated NH₃ gas to the uppermostsurface (base surface in forming the SiOCN film) of the wafer 200, theuppermost surface of the wafer 200 is changed (modified) into a surfacestate in which it is easy for the HCDS gas to be adsorbed onto theuppermost surface, and it is easy for Si to be deposited on theuppermost surface. That is, the nitride layer containing Si and N, theadsorption layer of the NH₃ gas, or both of these is/are formed at theuppermost surface of the wafer 200.

Moreover, when the cycle is performed a plurality of times, a reactioncaused, a layer formed, etc. in Step 1 in each cycle subsequent to thefirst cycle are similar to those in the surface modification step of thefirst sequence. That is, in this step, at least a portion of the thirdlayer formed in Step 4 described later is nitrided by supplying the NH₃gas into the processing chamber 201, thereby forming the fourth layercontaining silicon, oxygen, carbon, and nitrogen on the wafer 200. Also,in this step, by supplying the activated NH₃ gas to the surface of thethird layer, the uppermost surface of the fourth layer formed bynitridation of the third layer is changed (modified) into a surfacestate in which it is easy for the HCDS gas to be adsorbed onto theuppermost surface, and it is easy for Si to be deposited on theuppermost surface. That is, the nitride layer containing Si and N, theadsorption layer of the NH₃ gas, or both of these is/are formed at theuppermost surface of the fourth layer.

[Step 2]

Step 2 is performed similarly to Step 1 of the first sequence.Processing conditions, a reaction caused, a layer formed, etc. in Step 2are similar to those in Step 1 of the first sequence. That is, in thisstep, for example, a silicon-containing layer (first layer) of athickness of about less than one atomic layer to several atomic layersis formed on the wafer 200, and modified by the supply of the NH₃ gas,by supplying the HCDS gas into the processing chamber 201.

[Step 3]

Step 3 is performed similarly to Step 2 of the first sequence.Processing conditions, a reaction caused, a layer formed, etc. in Step 3are similar to those in Step 2 of the first sequence. That is, in thisstep, by supplying the C₃H₆ gas into the processing chamber 201, acarbon-containing layer is formed on the silicon-containing layer thatis the first layer formed in Step 2, and thus a second layer containingsilicon and carbon, namely, a layer in which the carbon-containing layeris formed on the silicon-containing layer, is formed on the wafer 200.

[Step 4]

Step 4 is performed similarly to Step 3 of the first sequence.Processing conditions, a reaction caused, a layer formed, etc. in Step 4are similar to those in Step 3 of the first sequence. That is, in thisstep, at least a portion of the second layer is oxidized by supplyingthe O₂ gas into the processing chamber 201, thereby forming the thirdlayer containing silicon, oxygen, and carbon on the wafer 200.

The above-described Steps 1 to 4 may be set as being included in onecycle, and by performing the cycle one or more times, the SiOCN film ofa predetermined film thickness may be formed on the wafer 200. Also, theabove-described cycle may be performed a plurality of times. In thiscase, a ratio of element components of the SiOCN layer, namely, a ratioof a silicon component, an oxygen component, a carbon component, and anitrogen component, namely, a silicon concentration, an oxygenconcentration, a carbon concentration, and a nitrogen concentration, maybe regulated by controlling a processing condition such as the internalpressure of the processing chamber 201, a gas supply time, or the likein each step, thereby controlling a composition ratio of the SiOCN film.In addition, the third layer, namely, the SiOCN layer, is formed on theuppermost surface of the SiOCN film formed in this step.

[Nitridation Step]

Steps 1 to 4 are set as being included in one cycle. The one cycle isperformed a predetermined number of times, and then the nitridation stepis performed. The nitridation step is performed similarly to Step 4 ofthe first sequence. Processing conditions, a reaction caused, a layerformed, etc. in this step are similar to those in Step 4 of the firstsequence. That is, in this step, at least a portion of the third layer(SiOCN layer) formed at the uppermost surface of the wafer 200 in thefinal cycle is nitrided by supplying the NH₃ gas into the processingchamber 201, thereby changing (modifying) the third layer into thefourth layer, namely, the SiOCN layer. The SiOCN film is a film in whichthe uppermost surface of the SiOCN film is appropriately nitrided tothereby be modified by the nitridation step, and thus a plurality of theSiOCN layers are stacked from a lowermost layer to an uppermost layer.That is, the SiOCN film is a film having a uniform composition in afilm-thickness direction.

(Gas Purge and Wafer Discharge)

When formation of the SiOCN film and modification of the uppermostsurface of the SiOCN film are performed, purging of the gas,substitution with the inert gas, returning to the atmospheric pressure,unloading of the boat, and discharging of the wafer are performedsimilarly to the first sequence.

(3) Effects According to Some Embodiments

According to some embodiments, one or a plurality of effects are shownas described later.

(a) In all of the film-forming sequences, the process of supplying theNH₃ gas may be performed before performing the process of supplying theHCDS gas, and the process of supplying the C₃H₆ gas and the process ofsupplying the O₂ gas may not performed until the process of supplyingthe HCDS gas is performed after the process of supplying the NH₃ gas isperformed. Accordingly, even in a low temperature range, a depositionrate of the SiOCN film can increase, thus enhancing a productivity offilm-forming processing.

That is, in the first sequence, Steps 1 to 4 are set as being includedin one cycle, and before the one cycle is performed a predeterminednumber of times, the surface modification step of supplying the NH₃ gasto the wafer 200 is performed. Step 2 of supplying the C₃H₆ gas and Step3 of supplying the O₂ gas are not performed between the surfacemodification step and Step 1. As described above, by performing thesurface modification step, the uppermost surface of the wafer 200 ischanged (modified) into a surface state in which it is easy for the HCDSgas to be adsorbed onto the uppermost surface, and it is easy for Si tobe deposited on the uppermost surface. Step 2 or Step 3 is not performedbetween the surface modification step and Step 1, and thus, theuppermost surface of the wafer 200 is maintained in a surface state inwhich it is easy for the HCDS gas to be adsorbed onto the uppermostsurface, and it is easy for Si to be deposited on the uppermost surface.Accordingly, in Step 1 performed immediately after the surfacemodification step, adsorption of the HCDS gas or deposition of Si ontothe uppermost surface of the wafer 200 is facilitated, and it isfacilitated to form a silicon-containing layer on the uppermost surfaceof the wafer 200.

Moreover, in the first sequence, Steps 1 to 4 are set as being includedin one cycle, and when the one cycle is performed a plurality of times,Step 4 of supplying the NH₃ gas and Step 1 of supplying the HCDS gas aresequentially performed in succession. Thus, Step 2 of supplying the C₃H₆gas and Step 3 of supplying the O₂ gas are not performed between Step 4and Step 1. As described above, the uppermost surface of the fourthlayer formed by performing Step 4 is changed (modified) into a surfacestate in which it is easy for the HCDS gas to be adsorbed onto theuppermost surface, and it is easy for Si to be deposited on theuppermost surface. Step 2 or Step 3 is not performed between Step 4 andStep 1, and thus, the uppermost surface of the fourth layer ismaintained in a surface state in which it is easy for the HCDS gas to beadsorbed onto the uppermost surface, and it is easy for Si to bedeposited on the uppermost surface. Accordingly, in Step 1 performedimmediately after Step 4, adsorption of the HCDS gas or deposition of Sionto the uppermost surface of the fourth layer is facilitated, and it isfacilitated to form a silicon-containing layer on the uppermost surfaceof the fourth layer.

Moreover, in the second sequence, Steps 1 to 4 are set as being includedin one cycle, which is performed a predetermined number of times. Thatis, Step 1 of supplying the NH₃ gas and Step 2 of supplying the HCDS gasare sequentially performed in succession, and Step 3 of supplying theC₃H₆ gas and Step 4 of supplying the O₂ gas are not performed betweenStep 1 and Step 2. As described above, by performing Step 1 in the firstcycle, the uppermost surface of the wafer 200 is changed (modified) intoa surface state in which it is easy for the HCDS gas to be adsorbed ontothe uppermost surface, and it is easy for Si to be deposited on theuppermost surface. Step 3 or Step 4 is not performed between Step 1 andStep 2, and thus, the uppermost surface of the wafer 200 is maintainedin a surface state in which it is easy for the HCDS gas to be adsorbedonto the uppermost surface, and it is easy for Si to be deposited on theuppermost surface. Accordingly, in Step 2 performed immediately afterStep 1, adsorption of the HCDS gas or deposition of Si onto theuppermost surface of the wafer 200 is facilitated, and it is facilitatedto form a silicon-containing layer on the uppermost surface of the wafer200.

Moreover, in the second sequence, Steps 1 to 4 are set as being includedin one cycle, and when the one cycle is performed a plurality of times,the uppermost surface of the fourth layer formed by performing Step 1 ischanged (modified) into a surface state in which it is easy for the HCDSgas to be adsorbed onto the uppermost surface, and it is easy for Si tobe deposited on the uppermost surface. Step 3 or Step 4 is not performedbetween Step 1 and Step 2, and thus, the uppermost surface of the fourthlayer is maintained in a surface state in which it is easy for the HCDSgas to be adsorbed onto the uppermost surface, and it is easy for Si tobe deposited on the uppermost surface. Accordingly, in Step 3 performedimmediately after Step 2, adsorption of the HCDS gas or deposition of Sionto the uppermost surface of the fourth layer is facilitated, and it isfacilitated to form a silicon-containing layer on the uppermost surfaceof the fourth layer.

As described above, in all of the film-forming sequences, it can befacilitated to form a silicon-containing layer on the uppermost surfaceof the wafer 200. Accordingly, even in the low temperature range, adeposition rate of the SiOCN film can increase, thus enhancing aproductivity of film-forming processing.

(b) According to some embodiments, in all of the film-forming sequences,when completing the process of forming the SiOCN film, the process ofsupplying the NH₃ gas is finally performed. That is, in the firstfilm-forming sequence, the activated NH₃ gas is supplied to the wafer200 in Step 4 that is performed in the final stage of each cycle. Also,in the second film-forming sequence, the cycle including Steps 1 to 4 isperformed a predetermined number of times, and then the nitridation stepof supplying the activated NH₃ gas to the wafer 200 is performed.Accordingly, the uppermost surface of the SiOCN film can beappropriately nitrided to thereby be modified, and thus, the finallyformed SiOCN film can have a uniform composition in a film-thicknessdirection.

(c) By rearranging the supply sequence of gases as in theabove-described first sequence or second sequence, the above-describedeffects can be obtained without changing the existing structure of thesubstrate processing apparatus, the existing film-forming temperature,and the existing kind and flow rate of the gases.

Moreover, at an initial state, an SiO film or a SiON film wasconsidered, instead of the SiOCN film, for forming by oxidizing and thennitriding a layer having Si—C bonding. Such films were considered sincebonding energy of Si—O bonding is greater than that of Si—N bonding orSi—C bonding, Si—C bonding of a layer having Si—C bonding is broken whenSi—O bonding is formed in oxidizing a layer having Si—C bonding, forwhich reason C that is decoupled from Si desorbs from the layer havingSi—C bonding, and it is difficult to form Si—N bonding even whennitridation is performed after the desorption. For this reason, it wasconsidered that when the supply sequence of gases is rearranged, forexample, like the above-described first sequence or second sequence, itis not possible to form the SiOCN film because C is all desorbed (i.e.,the SiO film or the SiON film is formed). The oxidizing power(especially, a dilution rate of an oxidizing gas, a supply time, and apartial pressure) was found to be controlled when the layer having Si—Cbonding is oxidized and then nitrided, and thus enables C, desorbed fromthe layer having Si—C bonding due to oxidation, to remain. Moreover, theSiOCN film can be formed by forming Si—N bonding through nitridationsubsequent thereto. According to the film-forming sequence describedabove, the above-described effects can be obtained at low cost withoutmuch change to the existing substrate processing apparatus.

(d) According to some embodiments, in all of the first sequence and thesecond sequence, a SiOCN film having an in-plane good uniformity of afilm thickness of a wafer can be formed. Furthermore, when the SiOCNfilm formed by the first sequence or second sequence is used as aninsulating film, it becomes possible to provide an in-plane uniformperformance of the SiOCN film, and it becomes possible to contribute toenhance a performance or yield rate of semiconductor devices.

(e) According to some embodiments, a ratio of element components of theSiOCN film, namely, a ratio of a silicon component, an oxygen component,a carbon component, and a nitrogen component, namely, a siliconconcentration, an oxygen concentration, a carbon concentration, and anitrogen concentration, may be regulated by controlling processingconditions such as the internal pressure of the processing chamber 201,a gas supply time, or the like in each step of each sequence, therebycontrolling a composition ratio of the SiOCN film.

(f) According to some embodiments, since a SiOCN film having apredetermined composition can be formed, it becomes possible to controlan etching resistance, a dielectric constant, and an insulatingresistance, and since the SiOCN film has a dielectric constant lowerthan that of a SiN film, it becomes possible to form a siliconinsulating film having a good etching resistance and a good insulatingresistance.

(g) In surface modification step and Steps 2 to 4 of the first sequenceand Steps 1, 3 and 4 and nitridation step of the second sequence, theC₃H₆ gas, the O₂ gas, and the NH₃ gas are activated by heat, andsupplied to the wafer 200. Accordingly, the above-described reactionscan be softly caused, and thus, formation, oxidation, and nitridation ofa carbon-containing layer can be easily performed in goodcontrollability.

(h) By using the silicon insulating film, as a sidewall spacer, it ispossible to provide technology for forming a device having a goodprocessability and a low leak current.

(i) By using the silicon insulating film, as an etch stopper, it ispossible to provide technology for forming a device having a goodprocessability.

(j) According to some embodiments, the silicon insulating film having anideal stoichiometric mixture ratio can be formed without using plasma.In addition, since the silicon insulating film can be formed withoutusing plasma, it is possible to provide technology that can be appliedto a process having a probability of plasma damage, for example, an SADPfilm of DPT.

Additional Embodiments

Hereinabove, various embodiments of the present disclosure has beenspecifically described, but the present disclosure is not limited to theabove-described embodiments, and may be varied without departing fromthe spirit of the present disclosure.

For example, in the above-described first sequence, the process (surfacemodification step) of supplying the NH₃ gas is performed, and then thecycle, in which the process (Step 1) of supplying the HCDS gas, theprocess (Step 2) of supplying the C₃H₆ gas, the process (Step 3) ofsupplying the O₂ gas, and the process (Step 4) of supplying the NH₃ aresequentially performed, is performed a predetermined number of times.However, the present disclosure is not limited the aspect. For example,as in FIG. 4B that shows a modification example of the first sequence,the surface modification step may be performed, and then a cycle inwhich Steps 1, 3, 2 and 4 are sequentially performed may be performed apredetermined number of times. That is, any one of the process (Step 2)of supplying the carbon-containing gas and the process (Step 3) ofsupplying the oxidizing gas may be first performed. However, the firstsequence of FIG. 4A in which Step 2 is performed prior to Step 3 canincrease a deposition rate more than the modification example of thefirst sequence of FIG. 4B in which Step 3 is performed prior to Step 2.

Moreover, for example, in the above-described second sequence, the cyclein which the process (Step 1) of supplying the NH₃ gas, the process(Step 2) of supplying the HCDS gas, the process (Step 3) of supplyingthe C₃H₆ gas, and the process (Step 4) of supplying the O₂ gas aresequentially performed is performed a predetermined number of times, andthen the process (nitridation step) of supplying the NH₃ is performed.However, the present disclosure is not limited the aspect. For example,as in FIG. 5B that shows a modification example of the second sequence,a cycle in which Steps 1, 2, 4 and 3 are sequentially performed may beperformed a predetermined number of times, and then the nitridation stepmay be performed. That is, any one of the process (Step 3) of supplyingthe carbon-containing gas and the process (Step 4) of supplying theoxidizing gas may be first performed. However, the second sequence ofFIG. 5A in which Step 3 is performed prior to Step 4 can increase adeposition rate more than the modification example of the first sequenceof FIG. 5B in which Step 4 is performed prior to Step 3.

Moreover, for example, the buffer chamber 237 may not be installed inthe processing chamber 201, and the NH₃ gas may be directly suppliedfrom the fourth nozzle 249 d into the processing chamber 201. In thiscase, the gas supply holes 250 d of the fourth nozzle 249 d may beopened toward a center of the reaction tube 203, and thus, the NH₃ gasfrom the fourth nozzle 249 d may be directly supplied toward the wafer200. Also, the fourth nozzle 249 d may not be provided, and only thebuffer chamber 237 may be provided.

Moreover, for example, the C₃H₆ gas, the O₂ gas, and the NH₃ gas are notlimited to a case in which the gases are activated by heat, and asanother example, the C₃H₆ gas, the O₂ gas, and the NH₃ gas may beactivated using plasma. In this case, for example, the gases may beplasma-excited using the above-described plasma source that is theplasma generator. When the gases are plasma-excited and supplied, afilm-forming temperature can be more lowered. However, when the gasesare not plasma-excited but are activated by heat as in theabove-described embodiments, particles can be prevented from occurringin the processing chamber 201, and moreover, plasma damage of themembers or the wafers 200 in the processing chamber 201 can be avoided.

Moreover, for example, in Step 3 of the first sequence and Step 4 of thesecond sequence, a reducing gas such as a hydrogen-containing gas may besupplied together with the oxidizing gas. When the oxidizing gas and thereducing gas are supplied into the processing chamber 201 under a lowatmosphere pressure (depressurization) lower than the atmosphericpressure, the oxidizing gas and the reducing gas may react with eachother in the processing chamber 201 to generate oxidative species thatcontains oxygen such as atomic oxygen but contains no water (H₂O), andthe layers may be oxidized by the oxidative species. In this case, thelayers can be oxidized at oxidizing power higher than a case in whichthe layers are oxidized by the oxidizing gas. The oxidation is performedunder a pressurization atmosphere of non-plasma. The reducing gas mayuse, for example, hydrogen (H₂) gas.

Moreover, for example, in the above-described embodiments, an examplewhich forms the SiOCN film (semiconductor insulating film) containingsilicon (semiconductor element) as a thin film has been described above,but the present disclosure may be applied to a case which forms a metaloxycarbonitride film (metal insulating film) containing metal elementssuch as titanium (Ti), zirconium (Zr), hafnium (Hf), tantalum (Ta),aluminum (Al), molybdenum (Mo), gallium (Ga), germanium (Ge), etc.

For example, the present disclosure may be applied to a case which formsa titanium oxycarbonitride film (TiOCN film), a zirconiumoxycarbonitride film (ZrOCN film), a hafnium oxycarbonitride film (HfOCNfilm), a tantalum oxycarbonitride film (TaOCN film), an aluminumoxycarbonitride film (AlOCN film), a molybdenum oxycarbonitride film(MoOCN film), a gallium oxycarbonitride film (GaOCN film), a germaniumfilm (GeOCN film), or a metal oxycarbonitride film formed by combinationor mixing thereof.

In this case, a film may be formed by a sequence (for example, the firstsequence, the second sequence, or the modification example thereof)similar to the above-described embodiments by using a metalelement-containing raw material gas (gas containing a metal element)such as a titanium raw material gas, a zirconium raw material gas, ahafnium raw material gas, a tantalum raw material gas, an aluminum rawmaterial gas, a molybdenum raw material gas, a gallium raw material gas,a germanium raw material gas, or the like, instead of a silicon rawmaterial gas in the above-described embodiments.

That is, in this case, the process of supplying the nitriding gas to thewafer is performed, and then a cycle including supplying the metalelement-containing gas to the wafer, supplying the carbon-containing gasto the wafer, and supplying the oxidizing gas to the wafer, andsupplying the nitriding gas to the wafer is performed a predeterminednumber of times, thereby forming a thin film (metal oxycarbonitridefilm) containing a metal element, oxygen, carbon, and nitrogen on thewafer. In the act of forming the metal oxycarbonitride film, the act ofsupplying the nitriding gas is performed before performing the processof supplying the metal element-containing gas, and the act of supplyingthe carbon-containing gas and the act of supplying the oxidizing gas arenot performed until the act of supplying the metal element-containinggas is performed after the act of supplying the nitriding gas isperformed.

For example, when a TiOCN film is formed as the metal oxycarbonitridefilm, a raw material containing Ti may use an organic raw material suchas tetrakis(ethylmethylamino)titanium (Ti[N(C₂H₅)(CH₃)]₄, abbreviation:TEMAT), tetrakis(dimethylamino)titanium (Ti[N(CH₃)₂]₄, abbreviation:TDMAT), tetrakis(diethylamido)titanium (Ti[N(C₂H₅)₂]₄, abbreviation:TDEAT), or the like, or use an inorganic raw material such as titaniumtetrachloride (TiCl₄) or the like. A gas similar to the above-describedembodiments may be used as the carbon-containing gas, the oxidizing gas,or the nitriding gas. Also, in this case, processing conditions may besimilar to the above-described embodiments. However, the wafertemperature may be set to fall within a range of, for example, 100 to500 degrees C., and the pressure in the processing chamber may be set tofall within a range of, for example, 1 to 3,000 Pa.

Moreover, for example, when a ZrOCN film is formed as the metaloxycarbonitride film, a raw material containing Zr may use an organicraw material such as tetrakis(ethylmethylamino)zirconium(Zr[N(C₂H₅)(CH₃)]₄, abbreviation: TEMAZ),tetrakis(dimethylamino)zirconium (Zr[N(CH₃)₂]₄, abbreviation: TDMAZ),tetrakis(diethylamido)zirconium (Zr[N(C₂H₅)₂]₄, abbreviation: TDEAZ), orthe like, or use an inorganic raw material such as zirconiumtetrachloride (ZrCl₄) or the like. A gas similar to the above-describedembodiments may be used as the carbon-containing gas, the oxidizing gas,or the nitriding gas. Also, in this case, processing conditions may besimilar to the above-described embodiments. However, the wafertemperature may be set to fall within a range of, for example, 100 to400 degrees C., and the pressure in the processing chamber may be set tofall within a range of, for example, 1 to 3,000 Pa.

Moreover, for example, when a HfOCN film is formed as the metaloxycarbonitride film, a raw material containing Hf may use an organicraw material such as tetrakis(ethylmethylamino)hafnium(Hf[N(C₂H₅)(CH₃)]₄, abbreviation: TEMAH), tetrakis(dimethylamino)hafnium(Hf[N(CH₃)₂]₄, abbreviation: TDMAH), tetrakis(diethylamido)hafnium(Hf[N(C₂H₅)₂]₄, abbreviation: TDEAH), or the like, or use an inorganicraw material such as hafnium tetrachloride (HfCl₄) or the like. A gassimilar to the above-described embodiments may be used as thecarbon-containing gas, the oxidizing gas, or the nitriding gas. Also, inthis case, processing conditions may be similar to the above-describedembodiments. However, the wafer temperature may be set to fall within arange of, for example, 100 to 400 degrees C., and the pressure in theprocessing chamber may be set to fall within a range of, for example, 1to 3,000 Pa.

Moreover, for example, when a TaOCN film is formed as the metaloxycarbonitride film, a raw material containing Ta may use an organicraw material such as tert-butylimido tris-diethylamino tantalum(Ta[N(C₂H₅)₂]₃[NC(CH₃)₃], abbreviation: TBTDET), tert-butyliminotri(ethylmethylamino)tantalum (Ta[NC(CH₃)]₃)[N(C₂H₅)CH₃]₃),abbreviation: TBTEMT), or the like, or use an inorganic raw materialsuch as tantalum pentachloride (TaCl₅) or the like. A gas similar to theabove-described embodiments may be used as the carbon-containing gas,the oxidizing gas, or the nitriding gas. Also, in this case, processingconditions may be similar to the above-described embodiments. However,the wafer temperature may be set to fall within a range of, for example,100 to 500 degrees C., and the pressure in the processing chamber may beset to fall within a range of, for example, 1 to 3,000 Pa.

Moreover, for example, when an AlOCN film is formed as the metaloxycarbonitride film, a raw material containing Al may use an organicraw material such as trimethyl aluminum (Al(CH₃)₃, abbreviation: TMA) orthe like, or use an inorganic raw material such as aluminum trichloride(AlCl₃) or the like. A gas similar to the above-described embodimentsmay be used as the carbon-containing gas, the oxidizing gas, or thenitriding gas. Also, in this case, processing conditions may be similarto the above-described embodiments. However, the wafer temperature maybe set to fall within a range of, for example, 100 to 400 degrees C.,and the pressure in the processing chamber may be set to fall within arange of, for example, 1 to 3,000 Pa.

Moreover, for example, when a MoOCN film is formed as the metaloxycarbonitride film, a raw material containing Mo may use an inorganicraw material such as molybdenum pentachloride (MoCl₅) or the like. A gassimilar to the above-described embodiments may be used as thecarbon-containing gas, the oxidizing gas, or the nitriding gas. Also, inthis case, processing conditions may be similar to the above-describedembodiments. However, the wafer temperature may be set to fall within arange of, for example, 100 to 500 degrees C., and the pressure in theprocessing chamber may be set to fall within a range of, for example, 1to 3,000 Pa.

As described above, the present disclosure may also be applied toformation of the metal oxycarbonitride film, in which case effectssimilar to one or more of the above-mentioned embodiments can beobtained. That is, the present disclosure may be applied to a case whichforms the oxycarbonitride film containing a specific element such as asemiconductor element, a metal element, or the like.

Moreover, an example in which the thin film is formed using a batch typesubstrate processing apparatus in which a plurality of substrates areprocessed at a time has been described, but the present disclosure isnot limited thereto but may be applied to a case in which the thin filmis formed using a single-wafer type substrate processing apparatus inwhich one or several substrates are processed at a time.

Moreover, the above-described embodiments, modification examples, andapplication examples may be appropriately combined and used.

In addition, the present disclosure is realized by varying, for example,a process recipe of the substrate processing apparatus of the relatedart. When the process recipe is varied, the process recipe according tothe present disclosure may be installed at the substrate processingapparatus of the related art via an electrical communication line or anon-transitory computer-readable recording medium in which the processrecipe is recorded, or the process recipe itself may be changed to theprocess recipe according to the present disclosure by manipulating aninput/output device of the substrate processing apparatus of the relatedart.

Example

As an example of the present disclosure, the substrate processingapparatus of FIGS. 1 and 2 is used, and a SiOCN film is formed on aplurality of wafers by the first sequence described previously. FIG. 6Ais a view showing a gas supply timing in the example. The HCDS gas isused as the silicon-containing gas, the C₃H₆ gas is used as thecarbon-containing gas, the O₂ gas is used as the oxidizing gas, and theNH₃ gas is used as the nitriding gas. A wafer temperature infilm-forming is set to 600 to 650 degrees C. Also, a gas supply time ofthe NH₃ gas in a surface modification step is set longer by four timesthan a gas supply time of the NH₃ gas in Step 4. Also, in order foroxidizing power in Step 3 to be weakened, a flow rate of the N₂ gassupplied into the processing chamber increases by about 3%, and apartial pressure of the O₂ gas in the processing chamber decreases.Other processing conditions are respectively set to predetermined valueswithin the processing conditions described above. In addition, a filmthickness of the SiOCN film formed on the wafers is measured.

Moreover, as a comparative example, the substrate processing apparatusof FIGS. 1 and 2 is used, and a SiOCN film is formed on a plurality ofwafers by a film-forming sequence in which a cycle, in which a step ofsupplying HCDS gas to the wafers, a step of supplying C₃H₆ gas to thewafers, a step of supplying NH₃ gas to the wafers, and a step ofsupplying O₂ gas to the wafers are sequentially performed, is performeda predetermined number of times. In the comparative example, only asupply sequence of gases differs from the above-described example. Thatis, except for the supply sequence of gases, processing conditions ofthe comparative example is the same as those of the above-describedexample. Furthermore, a film thickness of the SiOCN film formed on thewafers is measured.

FIG. 7 is a view showing a measurement result of film thicknesses of theSiOCN films in the example and comparative example of the presentdisclosure. The ordinate axis of FIG. 7 indicates an in-plane averagefilm thickness value A of the SiOCN film (formed on the wafer) in thewafer, and the abscissa axis indicates the example and the comparativeexample. In FIG. 7, the term “Top” indicates a measurement result of awafer disposed at an upper portion of a boat, the term “Cen” indicates ameasurement result of a wafer disposed at a central portion of the boat,and the term “Btm” indicates a measurement result of a wafer disposed ata lower portion of the boat.

As shown in FIG. 7, the film thickness of the SiOCN film in the exampleis an average (average in all of Top to Btm) of 187.8 Å, and the filmthickness of the SiOCN film in the comparative example is an average of163.3 Å. It can be seen that a deposition rate in the example increasesby 15% compared to a deposition rate in the comparative example. Thereason that processing conditions in the respective steps of supplyingthe HCDS gas, the C₃H₆ gas, the O₂ gas, and the NH₃ gas are the same isbecause the deposition rate of the SiOCN film depends on a thickness ofa silicon-containing layer formed per one cycle. In the example, theuppermost surface of the wafer or the uppermost surface of the fourthlayer, which is a plane for the HCDS gas or Si to be adsorbed thereon ora plane (basic plane) for the HCDS gas or Si to be deposited thereon, issupplied with the NH₃ gas to thereby be modified to a surface state(surface state in which a nitride layer, an adsorption layer of the NH₃gas, or all of these is/are formed on the uppermost surface) in which itis easy for the HCDS gas or Si to be adsorbed or deposited onto theuppermost surface. On the other than, in the comparative example, thestep of supplying the NH₃ gas is not performed before starting toperform the cycle, and when the cycle is repeated, the step of supplyingthe O₂ gas and the step of supplying the HCDS gas are successivelyperformed, whereby a plane for the HCDS gas or Si to be adsorbed thereonor a plane (basic plane) for the HCDS gas or Si to be deposited thereonhas relatively sufficient oxygen. A difference of the surface states isconsidered to be a factor that causes a difference of adsorption amountsor deposition amounts of HCDS gas or Si per one cycle, and thusincreases a deposition rate in the example.

<Further Additional Aspects of Present Disclosure>

Hereinafter, some aspects of the present disclosure will be additionallystated.

An aspect of the present disclosure provides a method of manufacturing asemiconductor device, including forming a thin film containing aspecific element, oxygen, carbon, and nitrogen on a substrate byperforming a cycle a predetermined number of times, the cycle including:supplying a specific element-containing gas to the substrate; supplyinga carbon-containing gas to the substrate; supplying an oxidizing gas tothe substrate; and supplying a nitriding gas to the substrate, whereinin the act of forming the thin film, the act of supplying the nitridinggas is performed before the act of supplying the specificelement-containing gas, and the act of supplying the carbon-containinggas and the act of supplying the oxidizing gas are not performed untilthe act of supplying the specific element-containing gas is performedafter the act of supplying the nitriding gas is performed.

In some embodiments, in the act of forming the thin film, the act ofsupplying the nitriding gas is performed, and then the cycle includingsupplying the specific element-containing gas, supplying thecarbon-containing gas, supplying the oxidizing gas, and supplying thenitriding gas is performed a predetermined number of times.

In some embodiments, in the act of forming the thin film, the act ofsupplying the nitriding gas is performed, and then the cycle, in whichthe act of supplying the specific element-containing gas, the act ofsupplying the carbon-containing gas, the act of supplying the oxidizinggas, and the act of supplying the nitriding gas are sequentiallyperformed, is performed a predetermined number of times.

In some embodiments, in the act of forming the thin film, the cycleincluding supplying the nitriding gas, supplying the specificelement-containing gas, supplying the carbon-containing gas, andsupplying the oxidizing gas is performed a predetermined number oftimes, and then the act of supplying the nitriding gas is performed.

In some embodiments, in the act of forming the thin film, the cycle, inwhich the act of supplying the nitriding gas, the act of supplying thespecific element-containing gas, the act of supplying thecarbon-containing gas, and the act of supplying the oxidizing gas aresequentially performed, is performed a predetermined number of times,and then the act of supplying the nitriding gas is performed.

In some embodiments, in the act of forming the thin film, an uppermostsurface of the substrate is modified by supplying the nitriding gas, anda specific element-containing layer containing the specific element isformed on the uppermost surface of the substrate modified by thenitriding gas by supplying the specific element-containing gas.

In some embodiments, in the act of forming the thin film, an uppermostsurface of the substrate is modified by supplying the nitriding gas, aspecific element-containing layer containing the specific element isformed on the uppermost surface of the substrate modified by thenitriding gas by supplying the specific element-containing gas, acarbon-containing layer is formed on the specific element-containinglayer by supplying the carbon-containing gas, a layer in which thecarbon-containing layer is formed on the specific element-containinglayer is oxidized by supplying the oxidizing gas to form a layercontaining the specific element, oxygen, and carbon, and then the layercontaining the specific element, oxygen, and carbon is nitrided bysupplying the nitriding gas to form the layer containing the specificelement, oxygen, carbon, and nitrogen, and an uppermost surface of theformed layer may be modified.

In some embodiments, when an uppermost surface of the substrate ismodified by supplying the nitriding gas, the uppermost surface of thesubstrate is nitrided, or the nitriding gas is adsorbed onto theuppermost surface of the substrate.

In some embodiments, the specific element is a semiconductor element ora metal element.

In some embodiments, the specific element is silicon.

Another aspect of the present disclosure provides a method ofmanufacturing a semiconductor device, including forming a thin filmcontaining a specific element, oxygen, carbon, and nitrogen on asubstrate by performing a cycle a predetermined number of times, thecycle including: supplying a specific element-containing gas to thesubstrate; supplying a carbon-containing gas to the substrate; supplyingan oxidizing gas to the substrate; and supplying a nitriding gas to thesubstrate, wherein in the act of forming the thin film, the act ofsupplying the nitriding gas is performed before the act of supplying thespecific element-containing gas, and the act of supplying thecarbon-containing gas and the act of supplying the oxidizing gas are notperformed until the act of supplying the specific element-containing gasis performed after the act of supplying the nitriding gas is performed.

Another aspect of the present disclosure provides a substrate processingapparatus including: a processing chamber configured to accommodate asubstrate; a specific element-containing gas supply system configured tosupply a specific element-containing gas to the substrate in theprocessing chamber; a carbon-containing gas supply system configured tosupply a carbon-containing gas to the substrate in the processingchamber; an oxidizing gas supply system configured to supply anoxidizing gas to the substrate in the processing chamber; a nitridinggas supply system configured to supply a nitriding gas to the substratein the processing chamber; and a controller configured to control thespecific element-containing gas supply system, the carbon-containing gassupply system, the oxidizing gas supply system, and the nitriding gassupply system such that a thin film containing a specific element,oxygen, carbon, and nitrogen is formed on the substrate by performing acycle a predetermined number of times, the cycle including supplying thespecific element-containing gas to the substrate, supplying thecarbon-containing gas to the substrate, supplying the oxidizing gas tothe substrate, and supplying the nitriding gas to the substrate, and inthe act of forming the thin film, the act of supplying the nitriding gasis performed before the act of supplying the specific element-containinggas, and the act of supplying the carbon-containing gas and the act ofsupplying the oxidizing gas are not performed until the act of supplyingthe specific element-containing gas is performed after the act ofsupplying the nitriding gas is performed.

Another aspect of the present disclosure provides a program that causesa computer to perform a process of forming a thin film containing aspecific element, oxygen, carbon, and nitrogen on a substrate byperforming a cycle a predetermined number of times, the cycle including:supplying a specific element-containing gas to the substrate; supplyinga carbon-containing gas to the substrate; supplying an oxidizing gas tothe substrate; and supplying a nitriding gas to the substrate, whereinin the act of forming the thin film, the act of supplying the nitridinggas is performed before the act of supplying the specificelement-containing gas, and the act of supplying the carbon-containinggas and the act of supplying the oxidizing gas are not performed untilthe act of supplying the specific element-containing gas is performedafter the act of supplying the nitriding gas is performed.

Another aspect of the present disclosure provides a non-transitorycomputer-readable recording medium storing program that causes acomputer to perform a process of forming a thin film containing aspecific element, oxygen, carbon, and nitrogen on a substrate byperforming a cycle a predetermined number of times, the cycle including:supplying a specific element-containing gas to the substrate; supplyinga carbon-containing gas to the substrate; supplying an oxidizing gas tothe substrate; and supplying a nitriding gas to the substrate, whereinin the act of forming the thin film, the act of supplying the nitridinggas is performed before the act of supplying the specificelement-containing gas, and the act of supplying the carbon-containinggas and the act of supplying the oxidizing gas are not performed untilthe act of supplying the specific element-containing gas is performedafter the act of supplying the nitriding gas is performed. According toa method of manufacturing a semiconductor device, a substrate processingapparatus, and a recording medium according to the present disclosure, adeposition rate can be prevented from being reduced when forming a thinfilm, including a specific element, oxygen, carbon, and nitrogen, in alow temperature range.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the disclosures. Indeed, the novel methods and apparatusesdescribed herein may be embodied in a variety of other forms;furthermore, various omissions, substitutions and changes in the form ofthe embodiments described herein may be made without departing from thespirit of the disclosures. The accompanying claims and their equivalentsare intended to cover such forms or modifications as would fall withinthe scope and spirit of the disclosures.

What is claimed is:
 1. A method of manufacturing a semiconductor device,comprising: (a) modifying an outermost surface of a substrate bysupplying a nitriding gas to the substrate; and (b) forming a thin filmcontaining a specific element, oxygen, carbon, and nitrogen on themodified outermost surface of the substrate by performing a cycle one ormore times, the cycle comprising sequentially performing: (b-1)supplying a specific element-containing gas to the substrate; (b-2)supplying an oxidizing gas to the substrate; (b-3) supplying acarbon-containing gas to the substrate; and (b-4) supplying a nitridinggas to the substrate.
 2. The method of claim 1, wherein, in the step(a), the outermost surface of the substrate is nitrided, or thenitriding gas is adsorbed onto the outermost surface of the substrate,or the outermost surface of the substrate is nitrided and the nitridinggas is adsorbed onto the outermost surface of the substrate at the sametime.
 3. The method of claim 1, wherein, in the step (a), a nitridelayer is formed on the outermost surface of the substrate, or anadsorption layer of the nitriding gas is formed on the outermost surfaceof the substrate, or the nitride layer and the adsorption layer areformed on the outermost surface of the substrate.
 4. The method of claim1, wherein, in the step (b-1), a specific element-containing layercontaining the specific element is formed on the modified outermostsurface of the substrate.
 5. The method of claim 1, wherein a specificelement-containing layer containing the specific element is formed onthe modified outermost surface of the substrate in the step (b-1); alayer containing the specific element and oxygen is formed by oxidizingthe specific element-containing layer in the step (b-2), a layercontaining the specific element, oxygen, and carbon is formed by forminga carbon-containing layer on the layer containing the specific elementand oxygen in the step (b-3); and the layer containing the specificelement, oxygen, and carbon is nitrided to form a layer containing thespecific element, oxygen, carbon, and nitrogen in the step (b-4).
 6. Themethod of claim 1, wherein a time for supplying the nitriding gas in thestep (a) is set to be longer than a time for supplying the nitriding gasin the step (b-4).
 7. The method of claim 1, wherein the specificelement is a semiconductor element or a metal element.
 8. The method ofclaim 1, wherein the specific element is silicon.
 9. A substrateprocessing apparatus comprising: a process chamber configured toaccommodate a substrate; a specific element-containing gas supply systemconfigured to supply a specific element-containing gas to the substratein the process chamber; a carbon-containing gas supply system configuredto supply a carbon-containing gas to the substrate in the processchamber; an oxidizing gas supply system configured to supply anoxidizing gas to the substrate in the process chamber; a nitriding gassupply system configured to supply a nitriding gas to the substrate inthe process chamber; and a controller configured to control the specificelement-containing gas supply system, the carbon-containing gas supplysystem, the oxidizing gas supply system, and the nitriding gas supplysystem such that a process of modifying an outermost surface of thesubstrate by supplying the nitriding gas to the substrate is performedand a process of forming a thin film containing a specific element,oxygen, carbon and nitrogen on the modified outermost surface of thesubstrate is performed by performing a cycle one or more times, thecycle comprising sequentially performing: supplying the specificelement-containing gas to the substrate; supplying the oxidizing gas tothe substrate; supplying the carbon-containing gas to the substrate; andsupplying the nitriding gas to the substrate.
 10. A non-transitorycomputer-readable recording medium storing a program that causes acomputer to perform a process of modifying an outermost surface of asubstrate by supplying a nitriding gas to the substrate in a processchamber and a process of forming a thin film containing a specificelement, oxygen, carbon, and nitrogen on the modified outermost surfaceof the substrate by performing a cycle one or more times, the cyclecomprising sequentially performing: supplying a specificelement-containing gas to the substrate in the process chamber;supplying an oxidizing gas to the substrate in the process chamber;supplying a carbon-containing gas to the substrate in the processchamber; and supplying a nitriding gas to the substrate in the processchamber.